invalidism, n. 1. sickness, infirmity, illness, vale tudinarianism, invalidity; weakening, weakness, feebleness, enfeeblement, frailty, frailness, helplessness; debilitation, debility, devitalization, decrepitude; exhaustion, prostration; disease, morbosity.
2. indisposition, confinement, hospitalization, disablement, incapacitation; retirement, superannuation; senescence, dotage, senility, decrepitude.
invalidity, n. 1. untenableness, inconclusiveness, unscientificness; illogicalness, illogicality, irrelevance, unreasonableness, senselessness, irrationality, incoherence, absurdity; falseness, falsity, fallacy, fallaciousness, erroneousness; speciousness, sophism, Logic. paralogism, elenchus, false refutation, perversion; inconsistency, incongruity, disparity; contradiction, antilogy.
2. weakness, weak point, ineffectualness, inefficacy; powerlessness, impotence, vulnerability; unconvincingness, lameness, vagueness, obscurity, flimsiness; futility, uselessness, nugacity, worthlessness; insipidness, pointlessness, vapidity; attenuation, dilution, indecisiveness, hesitancy, vacillation.
3. voidness, nullity, emptiness, invalidation. See - invalidation (defs. 3-5).
invaluable, adj. 1. precious, valuable, incalculably valuable, inestimably valuable, priceless, beyond price; dear, expensive, costly, high, high-priced, Inf. worth a pretty penny, Inf. worth its weight in gold, Inf. worth a king's ransom.
2. excellent, superexcellent, superlative, Inf. super; rare, golden, unusual, exceptional, extraordinary, unparalleled, unequaled, inimitable, matchless, peerless, unique, one of a kind; exquisite, superfine, capital, Inf. first-class, first-rate, Inf. top-drawer.
3. useful, very useful, nonexpendable, essential, requisite, required, needful, imperative, indispensable.
invariable, adj. 1. unchangeable, changeless, unchanging, constant, static, fixed, firm, fast, solid, steady, stable; permanent, abiding, enduring; immutable, unalterable, unmodifiable, untransformable, nonconvertible, incommutable, irreversible.
2. invariant, unvarying, unvaried; uniform, regular, always the same, identical, same, unbroken, all of a piece, homogeneous; even, symmetrical, smooth, level; stereotyped, clichd, undeviating, monotonous, dreary; systematic, methodical, reliable, dependable, unvacillating, unvicissitudinous, unfluctuating, unwavering, certain, sure.
3. recurrent, repeated, frequent, habitual; unremitting, relentless, persistent, perpetual, endless, never-ending, interminable, Sisyphean, ceaseless, incessant, unceasing.
invariability, n. 1. unchangeability, unchangeableness, unchangingness, changelessness, immutability; firmness, fastness, fixedness, solidity, steadiness, stability; permanence, permanency, incorruptibility, irreversibility; constancy, reliability, dependability, regularity, certainty, indubitability; incontrovertibility, incontestability, irrefutability.
2. frequency, habitude, habitualness; persistence, relentlessness, endlessness, interminableness, inter-minability, ceaselessness; incessancy, monotony, routine; uniformity, sameness, regularity, symmetry, symmetricalness; smoothness, levelness, evenness.
invariably, adv. 1. always, every time, at all times, on every occasion, without exception; constantly, regularly, repeatedly; continually, incessantly, uninterruptedly; day in, day out; inevitably, unfailingly, infallibly, surely, certainly.
2. perpetually, everlastingly, endlessly, unceasingly,