| Scrabble Word | Definition |
| imperceivable24 | that cannot be perceived; imperceptible |
| imperceptible23 | not perceptible, not detectable, too small in magnitude to be observed |
| impermissible21 | not permissible; not to be permitted or allowed |
| imperturbable21 | Not easily perturbed, upset or excited. |
| impracticable23 | not practicable; impossible or difficult in practice |
| inappreciable21 | insignificant, undetectable, not able to be noticed |
| incombustible21 | Not capable of catching fire and burning; not flammable. |
| inconceivable22 | Unable to be conceived or imagined; unbelievable. |
| incontestable17 | Not contestable; indisputable; certain |
| inconvertible20 | Not convertible |
| inconvincible22 | Incapable of being convinced. |
| incorruptible19 | Incapable of being bribed or morally corrupted; inflexibly just and upright. |
| indefatigable20 | Extremely persistent and untiring. |
| indescribable20 | Impossible (or very difficult) to describe. |
| indiscernible18 | Not capable of being discerned, of being perceived. |
| indispensable18 | (ecclesiastical, obsolete) Not admitting ecclesiastical dispensation; not subject to release or exemption; that cannot be allowed by bending the canonical rules. [16th-17th c.] |
| indissociable18 | Not dissociable |
| inexhaustible25 | Impossible to exhaust; unlimited. |
| inexplainable24 | That cannot be explained. |
| inexpressible24 | Unable to be expressed; not able to be put into words. |
| Scrabble Word | Definition |
| identifiable18 | Capable of being distinguished and named. |
| immeasurable18 | impossible to measure |
| immensurable18 | unmeasurable, immeasurable; not able to be measured, therefore connoting extremely large |
| impenetrable18 | Not penetrable. |
| imperishable21 | not perishable; not subject to decay; enduring permanently |
| imponderable19 | Not ponderable; without sensible or appreciable weight; incapable of being weighed. |
| inaccessible18 | Not able to be accessed; out of reach; inconvenient. |
| inadmissible17 | Not admissible, especially that cannot be admitted as evidence at a trial |
| inappeasable18 | That cannot be appeased. |
| inapplicable20 | Not applicable; that does not apply or cannot be applied; unsuitable or irrelevant. |
| incalculable18 | (not comparable) Too much, too vast, or too numerous to enable computation. |
| incommutable20 | Not commutable |
| incomparable20 | So much better than another as to be beyond comparison; matchless or unsurpassed. |
| incompatible20 | Of two things: that cannot coexist; not congruous because of differences; unable to function together due to dissimilarities. |
| incomputable20 | Not computable; that cannot be computed. |
| inconsolable16 | Not consolable; unable to be consoled or comforted, usually due to grief, disappointment, or other distress. |
| inconsumable18 | Not consumable; incapable of being consumed, wasted, or spent. |
| incorporable18 | Able to be incorporated. |
| incorrigible17 | Defective and impossible to materially correct or set aright. |
| indeclinable17 | That one cannot decline; unavoidable. |
| Scrabble Word | Definition |
| illimitable15 | Impervious to limitation, without limit. |
| illuminable15 | that can be illuminated or made lighter |
| immedicable20 | Incurable; not able to be assisted by medicine. |
| immitigable18 | That cannot be mitigated |
| impeachable22 | Able to be impeached (of a person). |
| impermeable19 | Impossible to permeate. |
| implantable17 | Capable of being, or designed to be, implanted (within the body etc.) |
| implausible17 | Not plausible; unlikely; dubious. |
| impregnable18 | (of a fortress, wall, etc., also figuratively) Too strong to be penetrated. |
| impressible17 | Capable of being impressed; susceptible of receiving impression. |
| inadvisable17 | unwise; not recommended; not prudent; not to be advised |
| inalienable13 | Incapable of being alienated, surrendered, or transferred to another; not alienable. |
| inalterable13 | That cannot be altered. |
| incoercible17 | Not to be coerced; incapable of being compelled or forced. |
| increasable15 | Able to be increased. |
| indefinable17 | That cannot be precisely defined or put into words. |
| indivisible17 | Incapable of being divided; atomic. |
| indomitable16 | Incapable of being subdued, overcome, or vanquished. |
| indubitable16 | clearly true; providing no possibility of doubt. |
| ineluctable15 | Impossible to avoid or escape; inescapable, irresistible. |
| Scrabble Word | Definition |
| illaudable13 | Not laudable; unpraiseworthy. |
| imaginable15 | Able to be imagined; conceivable |
| immersible16 | Not susceptible to harm if immersed in water. |
| immiscible18 | (physics, of two or more liquids) That are not mutually soluble; unmixable. |
| immortelle14 | Any of various papery flowers, often dried and used as decoration. |
| impalpable18 | Not able to be perceived by the senses (especially by touch); intangible or insubstantial. |
| impartible16 | not partible; not subject to partition; indivisible |
| impassable16 | (of a route, terrain, etc.) Incapable of being passed over, crossed, or negotiated. |
| impassible16 | (chiefly theology) Unable to suffer, or feel pain. |
| impeccable20 | Perfect, without faults, flaws or errors |
| implacable18 | Not able to be placated or appeased. |
| importable16 | (obsolete) Insupportable, unbearable. |
| impossible16 | Not possible; not able to be done or happen. |
| improbable18 | Not likely to be true. |
| improvable19 | Capable of being improved. |
| impugnable17 | That can be impugned; open to (verbal) attack, open to question. |
| inarguable13 | Not arguable; certain, incontestable or incontrovertible. |
| inclinable14 | Capable of being inclined or tilted. |
| includable15 | Alternative form of includible |
| includible15 | Suitable or available for inclusion. |
| Scrabble Word | Definition |
| ignitable12 | Capable of being ignited; able to burn. |
| ignitible12 | Capable of being ignited. |
| ignorable12 | That can be ignored. |
| illegible12 | Not clear enough to be read; unreadable; not legible or decipherable. |
| imageable14 | Capable of being imaged |
| imidazole21 | (organic chemistry) A heterocyclic organic compound containing two nitrogen atoms separated by a carbon atom in a five-membered ring, called 1,3-diazole in IUPAC nomenclature. |
| immovable18 | incapable of being physically moved; fixed |
| immutable15 | unable to be changed without exception. |
| imposable15 | Capable of being imposed or laid on. |
| imputable15 | That may be imputed |
| inaudible12 | Unable to be heard or not loud enough to be heard. |
| incapable15 | Not capable (of doing something); unable. |
| incitable13 | |
| incunable13 | Alternative form of incunabulum |
| incurable13 | Of an illness, condition, etc, that is unable to be cured; healless. |
| indelible12 | Having the quality of being difficult to delete, remove, wash away, blot out, or efface. |
| indexable19 | That can be indexed. |
| inducible14 | Able to be induced or caused. |
| inductile12 | Not ductile; incapable of being drawn into threads, as a metal. |
| ineffable17 | Beyond expression in words; unspeakable. [from 1450] |
| Scrabble Word | Definition |
| imbecile14 | (obsolete) A person with limited mental capacity who can perform tasks and think only like a young child, in medical circles meaning a person who lacks the capacity to develop beyond the mental age of a normal five to seven-year-old child. |
| imitable12 | Capable of being imitated or copied. |
| immingle13 | (obsolete) To mingle; to mix; to unite; to blend. |
| immobile14 | not mobile, not movable |
| immotile12 | Not motile (lacking the ability to move) |
| inarable10 | Not arable. |
| indocile11 | Unwilling to be taught or instructed; intractable or recalcitrant. |
| inedible11 | not edible; not appropriate, worthy, or safe to eat |
| instable10 | Exhibiting instability; unstable |
| intitule8 | (transitive, obsolete) To entitle; to give a title to. |
| inveigle12 | (transitive) To convert, convince, or win over with flattery or wiles. |
| inviable13 | Unable to sustain its own life |
| invirile11 | Deficient in manhood; unmanly; effeminate. |
| isolable10 | Able to be isolated. [from mid-19th c.] |
| issuable10 | (law) Leading to, producing, or relating to, an issue; capable of being made an issue at law. |
| Scrabble Word | Definition |
| icicle10 | A drooping, tapering shape of ice. |
| impale10 | (transitive) To pierce (something) with any long, pointed object. |
| indole7 | (organic chemistry) An organic compound, C8H7N, found in coal tar, and produced in the gut by the bacterial decomposition of tryptophan; it is an aromatic bicyclic heterocycle having a benzene ring fused with a pyrrole ring; indole and its derivatives occur widely in nature and have many industrial applications. |
| inhale9 | (intransitive) To draw air into the lungs, through the nose or mouth by action of the diaphragm. |
| insole6 | The inside sole of a shoe or other footwear. |