ill
Evil; wicked (of people).
Morally reprehensible (of behaviour etc.); blameworthy.
Indicative of unkind or malevolent intentions; harsh, cruel.
Unpropitious, unkind, faulty, not up to reasonable standard.
Unwell in terms of health or physical condition; sick.
Nauseated; having an urge to vomit.
Sublime, with the connotation of being so in a singularly creative way.
Extremely bad (bad enough to make one ill). Generally used indirectly with to be.
Unwise; not a good idea.
Bad-tempered.

illegitimate
Not conforming to known principles, or established or accepted rules or standards.
Not in accordance with the law.
Not sanctioned by marriage.
Not sanctioned by marriage.
Not sanctioned by marriage.
Not correctly deduced.
Not authorized by good usage; not genuine.
Involving the fertilization of pistils by stamens not of their own length, in heterogonously dimorphic and trimorphic flowers.

iller
comparative form of ill: more ill

illest
superlative form of ill: most ill

immature
Occurring before the proper time; untimely, premature (especially of death).
Not fully formed or developed; not grown.
Childish in behavior; juvenile.

immatures
plural of immature

immediate
Happening right away, instantly, with no delay.
Very close; direct or adjacent.
Manifestly true; requiring no argument.
Embedded as part of the instruction itself, rather than stored elsewhere (such as a register or memory location).
Used to denote that a transmission is urgent.
An artillery fire mission modifier for two types of fire mission to denote an immediate need for fire: Immediate smoke, all guns involved must reload smoke and fire. Immediate suppression, all guns involved fire the rounds currently loaded and then switch to high explosive with impact fused (unless fuses are specified).

immoral
Breaching principles of natural law, rectitude, or justice, and so inconsistent with the demands of virtue, purity, or "good morals"; not right, not moral. (Compare unethical, illegal.)

immunofluoropositive
Showing a positive reaction to immunofluorescence

immunopositive
That generates a positive response to a test for a specific antigen or antibody

imperial
Related to an empire, emperor, or empress.
Relating to the British imperial system of measurement.
Very grand or fine.
Of special, superior, or unusual size or excellence.
Stronger than typical. (Derived from the name of Russian Imperial stout, a strong dark beer.)

impolite
Not polite; discourteous; not of polished manners; wanting in good manners.

impoliter
comparative form of impolite: more impolite

impolitest
superlative form of impolite: most impolite

impolitic
Not in accordance with good policy.

impolitick
Obsolete form of impolitic.

impressive
Making, or tending to make, a positive impression; having power to impress.
Capable of being impressed.
Appealing.

improper
Unsuitable to needs or circumstances; inappropriate; inapt.
Not in keeping with conventional mores or good manners; indecent or immodest.
Not according to facts; inaccurate or erroneous.
Not consistent with established facts; incorrect.
Not properly named; See, for example, improper fraction.
Not specific or appropriate to individuals; general; common.
Of a complex random variable, correlated with its conjugate.

impropre
Obsolete form of improper.

incautious
careless, reckless, not exercising proper caution.

incorrect
Not correct; erroneous or wrong.
Faulty or defective.
Inappropriate or improper.

incorrects
plural of incorrect

incorrigible
Defective and impossible to materially correct or set aright.
Unmanageable; impervious to correction by punishment or pain.
Incurably depraved; not reformable.
Unchangeably established in a belief or habit.
Intrinsically incapable of being corrected; impossible to disprove, by its very nature.
Impossible to cure.

incorrigibles
plural of incorrigible

incredible
Too implausible to be credible; beyond belief.
Amazing; astonishing; awe-inspiring.
Marvellous; profoundly affecting; wonderful; excellent.

indecent
Offensive to good taste.
Not in keeping with conventional moral values; improper, immodest, or unseemly.
Generally unacceptable for public broadcasting but not legally obscene.

infirm
Weak or ill, not in good health.
Irresolute; weak of mind or will.
Frail; unstable; insecure.

infirmer
comparative form of infirm: more infirm

infirmest
superlative form of infirm: most infirm

informative
Providing information; especially, providing useful or interesting information.
Of a standard or specification, not specifying requirements, but merely providing information.
Formative; having power to form.

iniquitous
Characterized by iniquity (“deviation from what is right”).
Characterized by iniquity (“deviation from what is right”).

innocent
Free from guilt, sin, or immorality.
Bearing no legal responsibility for a wrongful act.
Without wrongful intent; accidental or in good faith.
Naive; artless.
Not harmful; innocuous; harmless; benign.
Lacking (something), or knowledge of it.
Lawful; permitted.
Not contraband; not subject to forfeiture.

inorder
To arrange; order; put in order.

insane
Exhibiting unsoundness or disorder of mind; not sane; utterly mad.
Used by or relating to insane people.
Causing insanity or madness.
Characterized by excess or the utmost folly; ridiculous; impractical.
Extremely good; incredibly amazing.
Enraged; furious.

insaner
comparative form of insane: more insane

insanery
An insane asylum.

insanest
superlative form of insane: most insane

inside
The interior or inner part.
The left-hand side of a road if one drives on the left, or right-hand side if one drives on the right.
The side of a curved road, racetrack etc. that has the shorter arc length; the side of a racetrack nearer the interior of the course or some other point of reference.
The interior organs of the body, especially the guts.
A passenger within a coach or carriage, as distinguished from one upon the outside.
The inside scoop; information known only to certain involved people.

interchiral
Between left-handed and right-handed forms (typically of an organic compound)
Between individuals of different chirality

intertubercular
Between tubercles.
Between tubercles.

intolerant
Unable or indisposed to tolerate, endure or bear.
Unable to digest food or be given substances of a certain composition without adverse effects.
Not tolerant; close-minded about new or different ideas; indisposed to tolerate contrary opinions or beliefs; impatient of dissent or opposition; denying or refusing the right of private opinion or choice in others; inclined to persecute or suppress dissent.

invalid
Not valid; not true, correct, acceptable or appropriate.

investive
Serving or tending to invest, or endow with a right or possession.

irrecoverable
Not recoverable; incapable of being recovered
That cannot be recovered from or made good; irremediable.

irreducible
Not able to be reduced or lessened.
Not able to be brought to a simpler or reduced form.
Unable to be factorized into polynomials of lower degree, as (x² + 1).
Whose numerator and denominator share no common factor greater than 1.
Unable to be factored into smaller integers; prime.
Whose only divisors are units and associates.
Inexpressible as the union of two proper algebraic subvarieties.
Not containing a sphere of codimension 1 that is not the boundary of a ball.
Impossible to divide further into representations of lower dimension by means of any similarity transformation.

irreducibles
plural of irreducible

irrefragable
Which cannot be refuted; clearly right, incontrovertible, indisputable, irrefutable.
Which cannot or should not be broken; indestructible.
Of a person: obstinate, stubborn.

irrefragible
Alternative spelling of irrefragable.

irrelevant
Not relevant, as
Not relevant, as:
Not relevant, as:
No longer famous or popular; washed up.

irrep
Clipping of irreducible representation.

irreps
plural of irrep