illogical.adjective
not observing the principles of logic; devoid of logic; senseless, such as this statement by Frederick Turner."The brain is hungry not for method but for content, especially content which contains generalizations that are powerful, precise and explicit.".and note the circular reasoning here
illogically.adverb
illogicality.noun,.plural.illogicalities
illogicalness.noun

insolence.noun,.plural.insolences
the state of being insolent; despitefulness; arrogance; impudence
insolent.adjective
if you say that someone is being insolent, you mean they are being rude to someone they ought to be respectful to; disrespectful of custom, methods or caring and helpful opinions and motives of others (decisions against proper and careful safety regulations evidence a rejectionist.motivated by either lack of concern or greed); impudent; arrogant
insolently.adverb

intrinsic.adjective
belonging to the essential nature or constitution of a thing (the intrinsic worth of a gem) (the intrinsic brightness of a star); contrast extrinsic
intrinsically.adverb

Grammar:.idiom.noun,.plural.idioms
an idiom is a group of words which have a different meaning when used together from the one they would have if you took the meaning of each word separately; a speech form or an expression of a given language that is peculiar to itself grammatically or cannot be understood from the individual meanings of its elements, as in 'talk turkey', 'take to heart', 'in spite of', 'by virtue of', etc.; the language peculiar to a people or to a district, community or class; dialect; the syntactical, grammatical or structural form peculiar to a language; manner; style

Grammar:.idiomatic.adjective
idiomatic means a speech form or an expression of a given language that is peculiar to itself grammatically or cannot be understood from the individual meanings of its elements, as in 'keep tabs on'; of, relating to or conforming to idiom;-peculiar to a particular group, individual or style
idiomatically.adverb
idiomaticness.noun

imbue, imbued, imbuing, imbues.transitive verbs
to permeate or influence as if by dyeing; to tinge or dye deeply 
synonym.infuse

imperceptible.adjective
extremely slight, gradual or subtle; not perceptible by the senses or mind
imperceptibly.adverb

imply, implied, implying, implies.transitive verbs
to hint; to indicate without saying openly or directly (his tone implied disapproval; although he didn't directly say it, he implied he would be soon moving into the country); suggest; to involve by logical necessity; entail (life implies learning and growth; to express or indicate.indirectly)

implication.noun,.plural.implications
the act of implicating or the condition of being implicated; the act of implying or the condition of being implied; an indirect indication (what are the implications of decisions one is considering?) a suggestion; an implied.meaning; something that is implied, especially; implicit.significance; to suggest; an inference
implicatively.adverb
implicative.adjective
implicate, implicated, implicating, implicates.transitive verbs
from Latin, to entwine.(to involve, to employ; intimately connected (what is the far reaching implication of his decision?); to implicate someone means to show or claim that they were involved in something having negative effect upon others; to have as a consequence, corollary or natural inference; to imply; to bring into intimate or incriminating connection; to involve in the nature or operation of something; entail (life implies growth through learning)l to involve or connect intimately or incriminatingly (evidence that implicates others in the plot); to have as a consequence or an inference; imply; to interweave or entangle

inculcate, inculcated, inculcating, inculcates, inculcated, inculcating.transitive verbs
to teach and impress upon the mind; to fix ideas, principles etc in someone's mind (she takes efforts to inculcate a sense of responsibility in her children; not all schools manage to successfully inculcate a love of learning); to make part of one's personality makeup by resolve, frequent.contemplation, instruction or repetition; instil; implant; indoctrinate; propagandize
inculcation.noun,.plural.inculcations
inculcator.noun,.plural.inculcators

insipid.adjective
devoid of qualities that make for spirit and character.(the new chilies are missing the fire we enjoyed earlier); lacking taste or savor; tasteless; lacking in qualities that interest, stimulate or challenge; dull, flat, boring, unintelligent, selfishly minded
insipidly.adverb
insipidity.noun,.plural.insipidities
insipidness.noun,.plural.insipidnesses
synonyms.vapid, flat, jejune, banal, inane
insipid implies a lack of sufficient taste or savor to please or interest (an insipid romance) 
vapid suggests a lack of liveliness, force or spirit (an exciting story given a vapid treatment)
flat applies to things that have lost their sparkle or zest (although well regarded in its day, the novel now seems flat)

inane, inaner, inanest.adjective
lacking.significance, meaning or point; silly; lacking sense or substance; empty (an inane comment; a ditzy person); implies a lack of any significant or convincing.quality (an inane interpretation of the play); unintelligent-
inanely.adverb
inanity.noun,.plural.inanities
something empty of meaning or sense; the quality.or.condition of being inane

itinerant.adjective
traveling from place to place, especially to perform work or a duty (an itinerant judge, itinerant labor)
itinerant.noun,.plural.itinerants
one who travels from place to place

irresolute.adjective
unsure of how to act or proceed; undecided; lacking in resolution; indecisive
irresolutely.adverb
irresolution.noun,.plural.irresolutions
irresoluteness.noun.(words ending in 'ess' are usually without pluralization - adding an 'es' making '...esses' is clumsy)

institutionalize, institutionalized, institutionalizing, institutionalizes.transitive verbs
to make part of a structured and usually well established system; to make into, treat as or give the character of an institution to; to place (an individual) in the care of an institution
institutionalization.noun,.plural.institutionalizations

institute, instituted, instituting, institutes.transitive verbs
to establish, organize and set in operation; to initiate; begin institute.noun,.plural.institutes
something instituted; an organization founded to promote a cause (a research institute); an educational institution, especially one for the instruction of technical subjects; the building or buildings housing such an institution
instituter.or.institutor.noun,.plural.instituters.or.institutors

institution.noun,.plural.institutions
buildings housing organizations of specialized efforts (a learning institution; a research institution); the act of instituting; customs, practices, relationships or behavioral patterns of importance in the life of a community or society (the institutions of Thanksgiving Day and the family); one long associated with a specified place, position or function; a place for the care of persons who are destitute, disabled or mentally ill

impact, impacted, impacting, impacts.verbs
transitive verb use.to have an effect or impact on; to pack firmly together; wedged or packed in, so as to fill or block an organ or a passage (impacted feces); to strike forcefully (meteorites impacting the lunar surface)
intransitive verb use.to have an effect or impact
impaction.noun,.plural.impactions
impact.noun,.plural.impacts
the power of making a strong, immediate impression (a speech that lacked impact); the effect or impression of one thing on another (still gauging the impact of automation on the lives of factory workers); the striking of one body against another; collision; the force or impetus transmitted by a collision

implausible.adjective
difficult to believe; not plausible; if you describe something as implausible, you believe that it is unlikely to be true (I had to admit it sounded like an implausible excuse; it's not entirely implausible that a galaxy could be similar to our own)
implausibility.noun,.plural.implausibilities
implausibleness.noun
implausibly.adverb

inalienable.adjective
if you say that someone has an inalienable right to something, you are emphasizing that they have a right to it which cannot be changed or taken awaythat cannot be transferred to another or others (inalienable or unalienable rights)
inalienably.adverb
inalienability.noun,.plural.inalienabilities

intellect.noun,.plural.intellects
the ability to learn and reason; the capacity for knowledge and understanding; the ability to think abstractly or profoundly; mind; a person of great intellectual ability; intelligent

inconsequential.adjective
lacking importance; not following from premises or evidence; illogical
inconsequentially.adverb
inconsequential.noun,.plural.inconsequentials
a triviality
inconsequentiality.noun,.plural.inconsequentialities
inconsequentialness.noun

immaterial.adjective
of no importance or relevance; inconsequential or irrelevant; having no material body or form
immaterially.adverb
immaterialness.noun

insubstantial.adjective
lacking substance or reality; immaterial; not firm or solid; flimsy; delicate; fine
insubstantiality.noun,.plural.insubstantialities

incorrupt, incorruptible.adjectives
not subject to corruption or decay; incapable of being morally corrupted
incorruptibly.adverb
incorruptibility.noun,.plural.incorruptibilities
incorruptness.noun
incorruption.noun,.plural.incorruptions
the quality or state of being free from physical decay; characterized by integrity or probity

intersect, intersected, intersecting, intersects.verbs
transitive verb use.to cut across or through (the path intersects the park); to form an intersection with; cross (the road intersects the highway a mile from here)
intransitive verb use.to cut across or overlap each other (circles intersecting on a graph); to form an intersection; cross (these two fences intersect at the creek)
intersection.noun,.plural.intersections
the act, process.or.result of intersecting; a place where things intersect, especially a place where two or more roads cross; in mathematics, the point or locus of points where one line, surface, or solid crosses another; a set that contains elements shared by two or more given sets

isthmus.noun,.plural.isthmuses.or.isthmi
a narrow strip of land connecting two larger masses of land

inefficient.adjective
not efficient, as lacking the ability or skill to perform effectively; incompetent (an inefficient manager); not producing the intended result; ineffective (an inefficient campaign against illegal drugs); wasteful of time, energy or materials (an inefficient design; outdated and inefficient methods)
inefficiently.adverb

inefficiency.noun, plural.inefficiencies
the quality, condition or fact of being inefficient; an inefficient act, design or procedure (pointed out certain inefficiencies in the many government and corporate concerns)