rebound.noun,.plural.rebounds
to bound back; spring back upon impact with something; a recoil; a rebound book
rebound, rebounded, rebounding, rebounds.verbs
intransitive verb use.to spring or bounce back after hitting or colliding with something; to recover, as exhaustion from too much exertion; resound (the sounds were bouncing back from the rocks as we walked and talked in the quiet valley passage); to retrieve and gain possession of a ball as it bounces off the backboard or rim after an unsuccessful shot, as in basketball
transitive verb use.to cause to rebound; a quick recovery from or reaction to disappointment or depression
rebounder.noun,.plural.rebounders
rebound.verb
past tense.and.past participle.of rebind
rebind, rebound, rebinding, rebinds.transitive verbs
to bind again, especially to put a new binding on a book
rebind.noun
a book that has been rebound (it was a rebind of an ancient book she gave to the historical society)

reservoir.noun,.plural.reservoirs
a place where anything is collected and stored

ribose.noun,.plural.riboses
a monosaccharide; a part of DNA and RNA
ribosome.noun,.plural.ribosomes
ribosomes are responsible for synthesizing-protein-(they build protein chains) and as such, are any of the RNA rich cytoplasmic granules that are sites of protein synthesis. Ribosomes have two sub units with bridges between them. Every time a ribosome builds a protein chain, a series of precisely synchronized-steps must occur at points within the chromosome, which is an intricate communication system; ribosomes are made of both nucleic acids and proteins. A ribosome is a particle in a cell-(an RNA protein complex) that assembles proteins by organizing (how?)-amino acids into particular sequences determined by the nucleotide sequence of RNA

radiography.noun,.plural.radiographies
the process by which radiographs are made
radiograph.noun,.plural.radiographs
an image produced on a radiosensitive surface, such as a photographic film, by radiation other than visible light, especially by x-rays passed through an object or by photographing a fluoroscopic image
radiograph, radiographed, radiographing, radiographs.transitive verbs
to make a radiograph of
radiographer.noun,.plural.radiographers
radiographic.adjective
radiographically.adverb
word radiograph is also called skiagraphy, which is a picture or photograph made up of shadows or outline

radiate, radiated, radiating, radiates.verbs
intransitive verb use.to send out rays or waves; to issue or emerge in rays or waves (heat radiated from the stove); to extend in straight lines from or toward a center; diverge or converge like rays: (spokes radiate from a wheel hub)
transitive verb use.to emit (light, for example) in or as if in rays; to send or spread out from or as if from a center (a cactus that radiates spines); to irradiate or illuminate an object; to manifest in a glowing manner (a girl who radiates her inner beauty) radiate.adjective
in botany, having rays or raylike parts, as in the flower heads of daisies; in biology, characterized by radial symmetry; surrounded with rays (a radiate head on a coin)
radiative.adjective

radiation.noun,.plural.radiations
a particle (that's what radiates); radiation is the emission of radiant energy.(a flow of any high speed energetic particles caused by spontaneous.disintegration of atomic-nuclei) as alpha and beta-particles or waves, such as electromagnetic radiation; specifically the process in which energy is sent out from heat, light, alpha and beta particles-(radioactivity); examples (energy traveling in the form of electromagnetic waves or photons; a stream of particles, especially alpha or beta particles from a radioactive source such as quarks or neutrons from a nuclear reactor (an atomic pile in which there is usually control of the atomic energy produced, but in the cases of Three Mile Island,  Fukushima and other locations, the disasters appeared be due to poor engineering designs that proved faulty); the Sun used to be thought to be a large hot nuclear reactor, but it's not that, it's much cooler inside than what are called sun spots exploding from it (the strange anomalies of space)
reradiation.noun,.plural.reradiations
reradiation is an emission following the absorption of incident.radiation; dangerous radiation can affect the human body

radioactivity.noun,.plural.radioactivities
spontaneous alteration of the nuclei of radioactive atoms, accompanied by the emission of radiation either directly from unstable.atomic.nuclei or as a consequence of a nuclear reaction; 3 types of radioactive radiation are alpha particles, beta particles, and gamma rays; why are some substances radioactive?
radioactive.adjective
of or exhibiting radioactivity
radioactively.adverb

radioisotope.noun,.plural.radioisotopes
a naturally or artificially produced radioactive isotope of an element

radiant.adjective
emitting heat or light; consisting of or emitted as radiation (radiant heat); filled with light; bright; glowing; beaming (after she changed her diet her skin became radiant)
radiant.noun,.plural.radiants
an object or a point from which light or heat rays are emitted
radiantly.adverb

radiance.also.radiancy.noun,.plural.radiances.also.radiancies.
the quality or state of being radiant
Physics:.the radiant energy emitted per unit time in a specified direction by a unit area of an emitting surface

radiant energy.noun,.plural.radiant energies
any form of energy radiating from a source, as electromagnetic waves, sound, heat, light, x-rays, gamma rays, etc.

radiator.noun,.plural.radiators
a radiator is a hollow metal device, usually connected by pipes to a central heating system in a home or apartment buildings, that is used to heat rooms; the radiator in a car is the part of the engine which is filled with a mixture of antifreeze and water in order to cool the engine and yet provide heat that radiates from pipes inside what's called the vehicle's heater

radon.noun,.plural.radons
symbol Rn; a colorless, radioactive, inert gaseous element formed by the radioactive decay of radium; it is used as a radiation source in radiotherapy and to produce neutrons for research; its most stable isotope is Rn 222 with a half-life of 3.82 days. Atomic number 86; melting point –71°C; boiling point –61.8°C; specific gravity (solid) 4. [rad(ium) + -on2.]

random.noun,.plural.randoms
without seeming aim, plan, purpose or method; as by chance; impetuous and haphazard movement or course of action; randomness.equates to confusion and disorder, evidencing lack of design,.until randomness is examined closely and understood
synonyms.desultory, haphazard, chance
randomly.adverb
randomness.noun.(normally used without being pluralized)

replica.noun,.plural.replicas
a copy or reproduction of a work of art, especially one made by the original artist; a copy or reproduction, especially one on a scale smaller than the original

replicate, replicated, replicating, replicates.verbs
transitive verb use.to duplicate, repeat (replicate a statistical experiment) 
intransitive verb use.to undergo replication; produce a replica of itself (virus particles replicating in cells) 
replicate.adjective
manifold, repeated 
replicate.noun,.plural.replicates
one of several identical experiments, procedures or samples 

replication.noun,.plural.replications
the act or process of duplicating or reproducing something (the model he built was an exact replication of the original full size automobile); in biology, the act or process by which genetic material, a cell or an organism reproduces or makes an exact copy of itself; an echo or a reverberation; a copy or reproduction; a fold or a folding back; a reply to an answer; a rejoinder
Law:.the plaintiff's response to the defendant's answer or plea

retina.noun,.plural.retinas.or.retinae
the innermost coat of the back part of the eye where the layer of cells sensitive to light are; it's a delicate, multilayered, light-sensitive membrane lining the inner eyeball and connected by the optic nerve to the brain; the image formed by this lens on the retina is carried to the brain by the optic nerve 
retinal.adjective

ratio.noun,.plural.ratios
a fixed relation in degree, number, etc. between two similar things; proportion.(a class of 30 with a ratio of 3 girls to 2 boys, would have 18 girls and 12 boys)

recapitulate, recapitulated, recapitulating, recapitulates.verbs
transitive verb use.to repeat in concise form; (re=again, ulation=a process)
Biology:.to appear to repeat (the evolutionary stages of the species) during the embryonic development of the individual organism
intransitive verb use.to make a summary
recapitulative.or.recapitulatory.adjective

recapitulation.noun,.plural.recapitulations
to recapitulate; repetition; repeat; restatement (a summary or concise.review); go through it again; repeat during development and growth; the act or process of recapitulating (evolutionary thinking)-ontogeny.recapitulates or repeats phylogeny, that is, as an embryo develops (ontogeny), it repeats the history of its species.(phylogeny); biogenesis, biosynthesis

recap, recapped, recapping, recaps.transitive verbs
to recapitulate (recapped the headlines at the end of the news broadcast)
recap.noun,.plural.recaps
a recapitulation, as of a news report

reciprocity.noun,.plural.reciprocities
mutual action; interchange; mutual.exchange; for every action there is a reaction set up and evidences.sometime, someway; reciprocity is the exchange of something between people when each person gives or allows something to the other
reciprocal.adjective
return in kind or degree (reap what we have sown); concerning each of two or more persons or things; given in return; to give and get; mutual
reciprocally.adverb
reciprocality.noun,.plural.reciprocalities
reciprocation.noun,.plural.reciprocations
reciprocate, reciprocated, reciprocating, reciprocates.verbs
transitive verb use.to give or take mutually; interchange; to show, feel or give in response or return
intransitive verb use.to move back and forth alternately; (a reciprocating saw to cut wood or metal); to give and take something mutually; to make a return for something given or done; to be complementary or equivalent
reciprocative.adjective
reciprocator.noun,.plural.reciprocators

refraction.noun,.plural.refractions
when a light wave moves from one medium.to another (as from air to glass), it moves with a different speed in the second medium; this change in speed causes its direction to change; amount of refraction depends on how dense the media is and other factors having to do with angle, speed, etc.; deflection from a straight path undergone by a light ray or energy wave in passing obliquely from one medium (as air) into another (as glass) in which its velocity is different; compare reflection
refractional.or.refractive.adjective
refractively.adverb
refractiveness.noun,.plural.refractivenesses.or
refractivity.noun,.plural.refractivities
refract, refracted, refracting, refracts.transitive verbs
to deflect light, for example from a straight path by refraction; to alter by viewing through a medium

refractory.adjective
obstinately.resistant; holding onto one's stubbornly.error filled ways in spite of information to the contrary; an unruly.manner; difficult to melt or work; resistant to heat (a refractory material such as silica); resistant to treatment (a refractory case of acne can be solved by eating sunflower seeds as they contain zinc; resistance to attempts to manage, treat or to mold (a refractory case of acne solved by eating sunflower seeds for the zinc); cantankerous; contentious; contumacious; disputatious; headstrong; intractable; mulish; recalcitrant; stiffnecked; uncontrollable; uncooperative; unmanageable; from 1600-1700 A.D., Latin 'refractarius' from 'refragari' meaning 'to oppose'
refractory.noun,.plural.refractories
one that is refractory; something or someone that is refractory; material that has a high melting point
refractorily.adverb
refractoriness.noun.(normally used without being pluralized)

repercussion.noun,.plural.repercussions
if an action or event has repercussions, it causes unpleasant things to happen some time after the original action or event; an often indirect effect, influence or result that is produced by an event or action; impact; a recoil, rebounding or reciprocal motion after impact; reflection
repercussive.adjective

reproach, reproached, reproaching, reproaches.transitive verbs
to bring accusation against (people often get reproached by the way they live and that by others who despise them); to express disapproval of, criticism of or disappointment in someone or something; admonish; to bring shame upon; disgrace; if you reproach someone, you say or show that you are disappointed, upset or angry because they have done something wrong (she is quick to reproach anyone who doesn't live up to her own high standards; she had not even reproached him for breaking his promise); if you look at or speak to someone with reproach, you show or say that you are disappointed, upset or angry because they have done something wrong (he looked at her with reproach; if you reproach yourself, you think with regret about something you have done wrong (we begin to reproach ourselves for not having been more careful)
reproach.noun,.plural.reproaches
blame; rebuke; one that causes rebuke or blame; disgrace; shame
beyond reproach.idiom
so good as to preclude any possibility of criticism
reproachable.adjective
reproachableness.noun.(normally used without being pluralized)
reproacher.noun,.plural.reproachers
reproachably.adverb
reproachful.adjective
expressing reproach or blame
reproachfully.adverb
reproachfulness.noun.(normally used without being pluralized)
self-reproach.noun.(normally used without being pluralized)

resplendent.adjective
splendid or dazzling in appearance; brilliant; if you describe someone or something as resplendent, you mean that their appearance is very impressive and expensive looking
resplendence.noun,.plural.resplendences.or
resplendency.noun,.plural.resplendencies
resplendently.adverb

resin.noun,.plural.resins
resin is a sticky substance that is produced by some trees (the ancients used resin mixed with other substances such as Earth to make pitch for sealing between the boards of their sailing ships); any of numerous clear to translucent yellow or brown, solid or semisolid, viscous substances of plant origin, such as balm, copal, rosin and amber, used principally in lacquers, varnishes, inks, adhesives, synthetic plastics and pharmaceuticals; any of numerous physically similar polymerized synthetics or chemically modified natural resins including thermoplastic materials such as polyvinyl, polystyrene and polyethylene and thermosetting materials such as polyesters, epoxies and silicones that are used with fillers, stabilizers, pigments and other components to form plastics
resin, resined, resining, resines.transitive verbs
to treat or rub with resin
resinous.adjective

rosin.noun,.plural.rosins
a translucent yellowish to dark brown resin.derived from the stumps or sap of various pine trees and used to increase sliding friction, as on the bows of certain stringed instruments and to manufacture a wide variety of products including varnishes, inks, linoleum, adhesives and soldering.compounds
rosin, rosined, rosining, rosins.transitive verbs
to coat or rub with rosin
rosiny.adjective
a solid slightly sticky substance that you rub on the bow of a violin etc, to help it move smoothly on the strings

raze, razed, razing, razes.transitive verbs
to level to the ground; demolish; ruin; to scrape or shave off

rase, rased, rasing, rases.transitive verbs
to erase

ribald.adjective.(pronounced 'rib uld')
characterized by or indulging in vulgar, lewd humor; coarse
ribald.noun,.plural.ribalds
a vulgar, lewdly funny individual, but one who is on to the con by controllers toward people (for example, the great George Carlin)