unsubstantial - 20 thesaurus results
| Main Entry: | unsubstantial |
| Part of Speech: | adjective1 |
| Definition: | flimsy |
| Synonyms: | fragile, frail, thin |
| Main Entry: | unsubstantial |
| Part of Speech: | adjective2 |
| Definition: | unreal |
| Synonyms: | imaginary, unbelievable, vaporous, visionary |
| Main Entry: | dreamy |
| Part of Speech: | adjective |
| Definition: | illusory, romantic |
| Synonyms: | abstracted, astral, calming, chimerical, daydreaming, excellent, fanciful, fantastic, gentle, idealistic, imaginary, immaterial, impractical, intangible, introspective, marvelous, misty, musing, mythical, nightmarish, otherworldly, out of this world, pensive, preoccupied, quixotic, shadowy, soothing, speculative, unreal, unsubstantial, utopian, vague, visionary, whimsical, introvertive, lulling, phantasmagoric, phantasmagorical, relaxing |
| Antonyms: | horrible, terrible, unromantic |
| Main Entry: | ethereal |
| Part of Speech: | adjective |
| Definition: | delicate, heavenly |
| Synonyms: | aerial, airy, celestial, dainty, divine, empyrean, exquisite, fairy, filmy, fine, gaseous, ghostly, gossamer, impalpable, insubstantial, intangible, light, rarefied, refined, spiritual, sublime, subtle, supernal, tenuous, unearthly, unsubstantial, unworldly, vaporous, empyreal, vapory |
| Antonyms: | earthly, indelicate, worldly |
| Main Entry: | frail |
| Part of Speech: | adjective |
| Definition: | breakable, weak |
| Synonyms: | brittle, dainty, decrepit, delicate, feeble, fishy, flimsy, fragile, infirm, insubstantial, puny, sad, sickly, slender, slight, slim, tender, tenuous, thin, unsound, unsubstantial, vulnerable, wishy-washy*, wispy, fracturable, frangible, shatterable, shattery, wimpy |
| Antonyms: | firm, strong, unbreakable |
* = informal/non-formal usage
| Main Entry: | futile |
| Part of Speech: | adjective |
| Definition: | hopeless, pointless |
| Synonyms: | abortive, barren, bootless, delusive, empty, exhausted, forlorn, fruitless, hollow, idle, impracticable, impractical, in vain, ineffective, ineffectual, insufficient, no dice, nugatory, on a treadmill, otiose, out the window, profitless, resultless, save one's breath, sterile, to no avail, to no effect, to no purpose, trifling, trivial, unavailing, unimportant, unneeded, unproductive, unprofitable, unreal, unsatisfactory, unsubstantial, unsuccessful, useless, vain, valueless, worthless |
| Antonyms: | fruitful, hopeful, productive, profitable |
| Main Entry: | illogical |
| Part of Speech: | adjective |
| Definition: | not making sense |
| Synonyms: | absurd, cockeyed*, fallacious, false, fatuous, faulty, groundless, hollow, implausible, inconclusive, incongruous, inconsistent, incorrect, invalid, irrational, irrelevant, mad, meaningless, nutty*, off the wall, preposterous, screwy*, senseless, specious, spurious, unconnected, unreasonable, unscientific, unsound, unsubstantial, untenable, wacky, casuistic, inconsequent, not following, self-contradictory, sophistic, sophistical, unproved, without basis, without foundation |
| Antonyms: | correct, logical, meaningful, rational, reasonable, right, sensible |
* = informal/non-formal usage
| Main Entry: | imaginary |
| Part of Speech: | adjective |
| Definition: | fictitious, invented |
| Synonyms: | abstract, apocryphal, apparitional, assumed, chimerical, deceptive, delusive, dreamed-up, dreamlike, dreamy, fabulous, fancied, fanciful, fantastic, fictional, figmental, fool's paradise, hallucinatory, hypothetical, ideal, illusive, illusory, imaginative, imagined, legendary, made-up, mythological, nonexistent, notional, phantasmal, phantasmic, quixotic, shadowy, spectral, supposed, supposititious, theoretical, trumped up*, unreal, unsubstantial, visionary, whimsical |
| Notes: | imaginary means not based on fact while imaginative means marked by independence and creativity in thought or action |
| Antonyms: | existing, factual, genuine, physical, real, substantial, true |
* = informal/non-formal usage
| Main Entry: | implausible |
| Part of Speech: | adjective |
| Definition: | not likely |
| Synonyms: | doubtful, dubious, far out, farfetched, fishy*, flimsy, for the birds, full of holes, impossible, improbable, inconceivable, incredible, obscure, problematic, puzzling, reachy, suspect, thin*, too much*, unbelievable, unconvincing, unreasonable, unsubstantial, weak, won't hold water, won't wash |
| Antonyms: | believable, likely, plausible, possibly, probably, reasonable |
* = informal/non-formal usage
| Main Entry: | improbable |
| Part of Speech: | adjective |
| Definition: | not likely |
| Synonyms: | doubtful, dubious, fanciful, far-fetched, flimsy*, iffy*, implausible, inconceivable, questionable, rare, slim, unbelievable, uncertain, unconvincing, unimaginable, unlikely, unsubstantial, weak, hundred-to-one, not expected, outside chance, slim and none, unheard of |
| Antonyms: | believable, likely, ostensible, plausible, possible, probable, tenable |
* = informal/non-formal usage
| Main Entry: | inconceivable |
| Part of Speech: | adjective |
| Definition: | beyond reason, belief |
| Synonyms: | extraordinary, fantastic, imcomprehensible, implausible, impossible, improbable, incogitable, incredible, insupposable, mind-boggling*, phony, rare, reachy, staggering, strange, thin*, unbelievable, unconvincing, unheard-of, unimaginable, unknowable, unlikely, unsubstantial, unthinkable, weak*, won't fly, won't wash |
| Antonyms: | believable, conceivable, fathomable, imaginable, reasonable |
* = informal/non-formal usage
| Main Entry: | infirm |
| Part of Speech: | adjective |
| Definition: | sick, weak |
| Synonyms: | ailing, anemic, debilitated, decrepit, delicate, failing, faint, feeble, flimsy, fragile, frail, halting, ill, insecure, irresolute, lame, shaky, unsound, unstable, unsubstantial, vacillating, wavering, wobbly, anile, enfeebled, faltering, laid low, sensile |
| Antonyms: | firm, healthy, hearty, robust, sound, strong |
| Main Entry: | insignificant |
| Part of Speech: | adjective |
| Definition: | not important; of no consequence |
| Synonyms: | casual, immaterial, inconsequential, infinitesimal, irrelevant, lesser, light, lightweight*, little, meager, meaningless, minimal, minor, minuscule, minute, negligible, nondescript, nonessential, nugatory, paltry, petty, pointless, scanty, secondary, senseless, small, trifling, trivial, unimportant, unsubstantial, inappreciable, inconsiderable, minim, not worth mentioning, purportless |
| Antonyms: | consequential, important, significant, substantial, valuable |
* = informal/non-formal usage
| Main Entry: | insubstantial |
| Part of Speech: | adjective |
| Definition: | weak, imaginary |
| Synonyms: | aerial, airy, chimerical, decrepit, ephemeral, false, fanciful, feeble, flimsy, fly-by-night*, fragile, frail, idle, illusory, immaterial, incorporeal, infirm, intangible, metaphysical, petty, poor, puny, slender, slight, tenuous, thin, unreal, unsound, unsubstantial, imponderable, too little too late |
| Antonyms: | real, strong, substantial |
* = informal/non-formal usage
| Main Entry: | intangible |
| Part of Speech: | adjective |
| Definition: | indefinite, obscured |
| Synonyms: | abstract, abstruse, airy, dim, elusive, ethereal, evanescent, evasive, hypothetical, impalpable, imperceptible, incorporeal, indeterminate, insensible, invisible, rare, shadowy, slender, slight, uncertain, unreal, unsubstantial, unsure, vague, eluding, evading, imponderable, inappreciable, unapparent, unobservable |
| Antonyms: | definite, obvious, palpable, perceptible, tangible |
| Main Entry: | jerry-built |
| Part of Speech: | adjective |
| Definition: | flimsy |
| Synonyms: | cheap, defective, insubstantial, makeshift, ramshackle, rickety, shoddy, slipshod, unsound, unsubstantial, jerry-rigged, junky |
| Main Entry: | less |
| Part of Speech: | adjective |
| Definition: | smaller, inferior |
| Synonyms: | beneath, deficient, depressed, lacking, lesser, limited, lower, minor, minus, negative, reduced, secondary, shorter, subordinate, unsubstantial, without, declined, diminished, excepting, fewer, not as great, shortened, slighter, subtracting |
| Antonyms: | more, superior, bigger |
| Main Entry: | limp |
| Part of Speech: | adjective |
| Definition: | not stiff; weak |
| Synonyms: | bending, debilitated, drooping, droopy, ductile, enervated, exhausted, feeble, flabby, flaccid, flexible, flimsy, floppy, impressible, infirm, languid, languishing, lax, lethargic, limber, listless, loose, plastic, pliable, pliant, slack, soft, spent, spiritless, supple, tired, unsubstantial, weakened, worn out, yielding, flexuous, relaxed, wearied |
| Antonyms: | hard, inflexible, rigid, stiff, straight, strong, unbending |
| Main Entry: | metaphysical |
| Part of Speech: | adjective |
| Definition: | not physical; without physical presence |
| Synonyms: | abstract, abstruse, deep, difficult, esoteric, eternal, fundamental, high-flown, ideal, immaterial, impalpable, incorporeal, insubstantial, intangible, intellectual, mystical, philosophical, preternatural, profound, recondite, spiritual, superhuman, superior, supernatural, theoretical, transcendental, unearthly, universal, unreal, unsubstantial, bodiless, discarnate, jesuitic, nonmaterial, nonphysical, numinous, oversubtle, supermundane, suprahuman, supramundane, supranatural, unfleshly, unphysical |
| Antonyms: | concrete, material, objective, physical, real, solid, substantial |
| Main Entry: | nonexistent |
| Part of Speech: | adjective |
| Definition: | fictional, not real |
| Synonyms: | absent, airy, baseless, blank, chimerical, dead, defunct, departed, dreamlike, dreamy, empty, ethereal, extinct, flimsy, gone, groundless, hypothetical, illusory, imaginary, imagined, immaterial, insubstantial, legendary, lost, missing, mythical, negative, null, null and void*, shadowy, tenuous, unreal, unsubstantial, vacant, vague, vaporous, void, extinguished, fancied, few and far between, gossamery, hallucinatory, imponderable, passed away, passed on, perished, ungrounded, without foundation |
| Antonyms: | actual, existing, real, true, existent |
* = informal/non-formal usage
Roget's 21st Century Thesaurus, Third Edition
Copyright © 2009 by the Philip Lief Group.
Cite This Source
Roget's 21st Century Thesaurus, Third Edition
Copyright © 2009 by the Philip Lief Group.
Cite This Source
Copyright © 2009, Dictionary.com, LLC. All rights reserved.

