Synonyms for Un substantial:

• adj.

  •bodiless (adjective)
  • unbodied,
  • discorporate.
  •dreamy (adjective)
  • out of this world,
  • introvertive,
  • quixotic,
  • idealistic,
  • immaterial,
  • mythical,
  • fantastic,
  • speculative,
  • abstracted,
  • utopian,
  • phantasmagoric,
  • introspective,
  • otherworldly,
  • gentle,
  • preoccupied,
  • relaxing,
  • soothing,
  • calming,
  • unsubstantial,
  • musing,
  • impractical,
  • whimsical,
  • excellent,
  • fanciful,
  • phantasmagorical,
  • astral,
  • daydreaming,
  • pensive,
  • chimerical,
  • misty,
  • nightmarish,
  • intangible,
  • vague,
  • lulling,
  • marvelous.
  •empty (adjective)
  • insipid,
  • vapid,
  • aimless,
  • banal,
  • insincere,
  • otiose,
  • jejune,
  • futile,
  • unsatisfactory,
  • hollow,
  • vain,
  • valueless,
  • ineffectual,
  • unintelligent,
  • silly,
  • frivolous,
  • petty,
  • fatuous,
  • devoid,
  • idle,
  • purposeless,
  • dumb,
  • cheap,
  • ignorant,
  • dead,
  • flat,
  • vacuous,
  • trivial,
  • nugatory,
  • barren,
  • worthless,
  • inexpressive,
  • meaningless,
  • dishonest,
  • paltry,
  • expressionless,
  • deadpan,
  • senseless.
  •ethereal (adjective)
  • light,
  • subtle,
  • fairy,
  • exquisite,
  • refined,
  • ghostly,
  • unearthly,
  • filmy,
  • insubstantial,
  • airy,
  • impalpable,
  • gossamer,
  • celestial,
  • sublime,
  • dainty,
  • fine,
  • unworldly,
  • spiritual,
  • supernal,
  • Vapory,
  • rarefied,
  • tenuous,
  • divine,
  • empyrean,
  • empyreal,
  • gaseous.
  •flimsy (adjective)
  • cut-rate,
  • assailable,
  • slapdash,
  • inconceivable,
  • trifling,
  • weakly,
  • shaky,
  • rickety,
  • groundless,
  • infirm,
  • fallacious,
  • gauzy,
  • wobbly,
  • incredible,
  • tacky,
  • contemptible,
  • delicate,
  • sleazy,
  • decrepit,
  • inadequate,
  • papery,
  • illogical,
  • lame,
  • slight,
  • rinkydink,
  • meager,
  • baseless,
  • weak,
  • puerile,
  • defective,
  • unreasonable,
  • transparent,
  • unsound,
  • false,
  • unpersuasive,
  • sheer,
  • Controvertible,
  • house of cards,
  • ungrounded,
  • inept,
  • wishful,
  • shallow,
  • superficial,
  • improbable,
  • feeble,
  • chiffon,
  • poor.
  •floating (adjective)
  • unattached,
  • volatile,
  • free,
  • soaring,
  • unsinkable,
  • nonsubmersible,
  • inflated,
  • sailing,
  • Hovering,
  • Wafting,
  • swimming.
  •frail (adjective)
  • shatterable,
  • tender,
  • wimpy,
  • slender,
  • flimsy,
  • frangible,
  • wishy-washy,
  • sad,
  • vulnerable,
  • fishy,
  • sickly,
  • slim,
  • fracturable,
  • Shattery,
  • brittle,
  • puny,
  • wispy.
  •futile (adjective)
  • insufficient,
  • fruitless,
  • exhausted,
  • unavailing,
  • unsuccessful,
  • unproductive,
  • unprofitable,
  • bootless,
  • forlorn,
  • on a treadmill,
  • useless,
  • in vain,
  • sterile,
  • unimportant,
  • no dice,
  • profitless,
  • to no avail,
  • impracticable,
  • Resultless,
  • to no effect,
  • out the window,
  • empty,
  • delusive,
  • abortive,
  • save one's breath,
  • ineffective,
  • unneeded,
  • to no purpose.
  •illogical (adjective)
  • screwy,
  • unproved,
  • wacky,
  • irrational,
  • untenable,
  • mad,
  • sophistical,
  • casuistic,
  • sophistic,
  • self-contradictory,
  • cockeyed,
  • inconclusive,
  • irrelevant,
  • faulty,
  • spurious,
  • invalid,
  • nutty,
  • incorrect,
  • absurd,
  • preposterous,
  • unconnected,
  • unscientific,
  • off the wall,
  • inconsequent,
  • specious,
  • incongruous,
  • not following,
  • inconsistent,
  • without foundation,
  • implausible,
  • without basis.
  •imaginary (adjective)
  • trumped up,
  • figmental,
  • imagined,
  • dreamlike,
  • abstract,
  • apparitional,
  • ideal,
  • notional,
  • hallucinatory,
  • spectral,
  • mythological,
  • illusive,
  • phantasmal,
  • made-up,
  • fool's paradise,
  • imaginative,
  • legendary,
  • supposititious,
  • apocryphal,
  • dreamy,
  • assumed,
  • supposed,
  • theoretical,
  • fabulous,
  • illusory,
  • dreamed-up,
  • fictional,
  • hypothetical,
  • fancied,
  • nonexistent,
  • phantasmic,
  • deceptive.
  •immaterial (adjective)
  • spiritlike,
  • Disbodied,
  • nonmaterial,
  • supernatural,
  • Unfleshly,
  • metaphysical,
  • incorporate,
  • imponderable,
  • bodiless,
  • wraithlike,
  • insensible,
  • Discarnate,
  • psychic,
  • incorporeal,
  • nonphysical,
  • heavenly,
  • unembodied,
  • subjective,
  • Asomatous,
  • disembodied.
  •implausible (adjective)
  • won't wash,
  • too much,
  • dubious,
  • farfetched,
  • puzzling,
  • doubtful,
  • full of holes,
  • obscure,
  • impossible,
  • for the birds,
  • far out,
  • problematic,
  • reachy,
  • won't hold water,
  • unconvincing,
  • suspect.
  •improbable (adjective)
  • slim and none,
  • unimaginable,
  • hundred-to-one,
  • not expected,
  • rare,
  • unheard of,
  • far-fetched,
  • questionable,
  • outside chance,
  • uncertain,
  • unlikely,
  • iffy.
  •inconceivable (adjective)
  • won't fly,
  • strange,
  • Incogitable,
  • Insupposable,
  • phony,
  • unthinkable,
  • unknowable,
  • mind-boggling,
  • imcomprehensible,
  • staggering,
  • unheard-of,
  • extraordinary.
  •incredible (adjective)
  • outlandish,
  • out of the question,
  • rings phony,
  • ridiculous.
  •infirm (adjective)
  • sensile,
  • ill,
  • irresolute,
  • faltering,
  • anile,
  • debilitated,
  • laid low,
  • failing,
  • insecure,
  • anemic,
  • faint,
  • halting,
  • wavering,
  • vacillating,
  • ailing,
  • enfeebled,
  • unstable.
  •insignificant (adjective)
  • not worth mentioning,
  • infinitesimal,
  • inconsiderable,
  • minimal,
  • Purportless,
  • minor,
  • negligible,
  • minim,
  • nondescript,
  • nonessential,
  • casual,
  • scanty,
  • pointless,
  • lightweight,
  • inconsequential,
  • inappreciable,
  • minuscule,
  • small,
  • little,
  • minute,
  • lesser,
  • secondary.
  •insubstantial (adjective)
  • too little too late,
  • fly-by-night,
  • ephemeral.
  •intangible (adjective)
  • eluding,
  • imperceptible,
  • unapparent,
  • abstruse,
  • Evading,
  • invisible,
  • dim,
  • unobservable,
  • indeterminate,
  • evanescent,
  • elusive,
  • evasive,
  • unsure.
  •jerry-built (adjective)
  • slipshod,
  • junky,
  • ramshackle,
  • makeshift,
  • jerry-rigged,
  • shoddy.
  •less (adjective)
  • not as great,
  • Without,
  • minus,
  • subordinate,
  • shorter,
  • lower,
  • fewer,
  • diminished,
  • beneath,
  • Excepting,
  • limited,
  • Subtracting,
  • reduced,
  • lacking,
  • negative,
  • depressed,
  • Declined,
  • shortened,
  • Slighter,
  • deficient.
  •light (adjective)
  • tissuelike,
  • sylphlike,
  • effervescent,
  • fragmentary,
  • porous,
  • fractional,
  • floating,
  • fluffy,
  • nimble,
  • graceful,
  • frugal,
  • easy,
  • portable,
  • insignificant,
  • sandy,
  • crumbly,
  • tiny,
  • unheavy,
  • restricted,
  • sprightly,
  • modest,
  • downy,
  • lithe,
  • not many,
  • friable,
  • Imponderous,
  • hardly enough,
  • atmospheric,
  • loose,
  • moderate,
  • light-footed,
  • agile,
  • sparse,
  • Gossamery,
  • spongy,
  • weightless,
  • indistinct,
  • wee,
  • not much,
  • featherweight,
  • shoestring,
  • hardly any,
  • mild,
  • buoyant,
  • digestible,
  • frothy,
  • feathery,
  • not rich,
  • Floatable,
  • soft.
  •limp (adjective)
  • listless,
  • relaxed,
  • lax,
  • supple,
  • ductile,
  • plastic,
  • bending,
  • pliable,
  • impressible,
  • wearied,
  • drooping,
  • pliant,
  • enervated,
  • spent,
  • limber,
  • worn out,
  • floppy,
  • lethargic,
  • slack,
  • flexible,
  • droopy,
  • weakened,
  • Languishing,
  • tired,
  • flaccid,
  • yielding,
  • languid,
  • spiritless,
  • flexuous,
  • flabby.
  •metaphysical (adjective)
  • preternatural,
  • mystical,
  • recondite,
  • supranatural,
  • high-flown,
  • esoteric,
  • transcendental,
  • universal,
  • profound,
  • difficult,
  • oversubtle,
  • superior,
  • eternal,
  • Supermundane,
  • jesuitic,
  • philosophical,
  • fundamental,
  • numinous,
  • Supramundane,
  • suprahuman,
  • unphysical,
  • intellectual,
  • deep,
  • superhuman.
  •moony (adjective)
  • woolgathering.
  •nonexistent (adjective)
  • few and far between,
  • null,
  • void,
  • lost,
  • defunct,
  • departed,
  • Perished,
  • extinguished,
  • vacant,
  • blank,
  • gone,
  • missing,
  • null and void,
  • passed on,
  • absent,
  • extinct,
  • passed away.
  •nonphysical (adjective)
  • uncorporal.
  •notional (adjective)
  • fantastical,
  • conceptual,
  • chimeric.
  •pale (adjective)
  • livid,
  • sick,
  • whitish,
  • colorless,
  • pallid,
  • faded,
  • waxen,
  • deathlike,
  • haggard,
  • ashen,
  • gray,
  • ghastly,
  • ashy,
  • sallow,
  • blanched,
  • doughy,
  • waxlike,
  • pasty,
  • wan,
  • white,
  • lurid,
  • washed-out,
  • bleached,
  • cadaverous,
  • bloodless,
  • dull.
  •puny (adjective)
  • small-fry,
  • Unconsequential,
  • runt,
  • small time,
  • picayune,
  • inferior,
  • stunted,
  • pint-sized,
  • zero,
  • undersized,
  • shrimp,
  • peanut,
  • niggling,
  • two-bit,
  • undeveloped,
  • half-pint,
  • nothing,
  • zilch,
  • peewee,
  • underfed,
  • measly,
  • piddling,
  • diminutive.
  •shadowy (adjective)
  • umbral,
  • shady,
  • dark,
  • cloudy,
  • adumbral.
  •sleazy (adjective)
  • common,
  • mean,
  • sordid,
  • base,
  • run-down,
  • shabby,
  • broken-down,
  • squalid,
  • seedy,
  • limp,
  • dilapidated,
  • low,
  • trashy.
  •thick (adjective)
  • unjust,
  • unfair,
  • excessive.
  •thin (adjective)
  • paper-thin,
  • stretched,
  • translucent,
  • sketchy,
  • diluted,
  • permeable,
  • wafer-thin,
  • scarce,
  • thick,
  • attenuated,
  • scattered,
  • skimpy,
  • see-through,
  • Subtile,
  • attenuate,
  • scant,
  • weak-kneed.
  •unbelievable (adjective)
  • scatterbrained,
  • past belief,
  • astonishing,
  • kooky,
  • open to doubt,
  • flaky,
  • cockamamie,
  • harebrained,
  • beyond belief,
  • lamebrained,
  • reaching.
  •unreal (adjective)
  • Storybook,
  • mock,
  • romantic,
  • invented,
  • fictive,
  • suppositious,
  • misleading,
  • pretended,
  • sham,
  • ostensible,
  • artificial,
  • fictitious,
  • nebulous,
  • fabled,
  • seeming.
  •unsound (adjective)
  • not solid,
  • erroneous,
  • unbacked,
  • unsteady,
  • unwell,
  • diseased,
  • unsafe,
  • demented,
  • crazed,
  • insane,
  • deranged,
  • lunatic,
  • flawed,
  • inaccurate,
  • tottering,
  • unhealthy,
  • in poor health,
  • unbalanced,
  • unreliable,
  • dangerous,
  • unhinged.
  •unsubstantial (adjective)
  • shadowy,
  • fragile,
  • ethereal,
  • vaporous,
  • inane,
  • frail,
  • unreal,
  • thin,
  • visionary,
  • unbelievable,
  • imaginary,
  • diaphanous,
  • aerial,
  • filigree.
  •waterish (adjective)
  • watery.
  •weak (adjective)
  • out of gas,
  • Impuissant,
  • senile,
  • immature,
  • effete,
  • green,
  • prostrate,
  • supine,
  • pathetic,
  • undependable,
  • spineless,
  • raw,
  • torpid,
  • spindly,
  • languorous,
  • rotten,
  • sluggish,
  • unqualified,
  • forceless,
  • impotent,
  • handicapped,
  • unprepared,
  • untrained,
  • incompetent,
  • rocky,
  • wasted,
  • lackadaisical,
  • powerless,
  • incomplete,
  • substandard,
  • wanting,
  • hesitant.
  •weightless (adjective)
  • light as a feather.
  •wrong (adjective)
  • untrue,
  • not working,
  • not right,
  • mistaken,
  • out of line,
  • out of commission,
  • fluffed,
  • askew,
  • Misconstrued,
  • wide,
  • astray,
  • bad,
  • out,
  • at fault,
  • miscalculated,
  • misguided,
  • out of order,
  • inexact,
  • amiss,
  • perverse,
  • mishandled,
  • in error,
  • on the wrong track,
  • erratic,
  • goofed,
  • counterfactual,
  • misfigured,
  • erring,
  • off-target,
  • awry,
  • not precise.

Antonyms for Un substantial:

• adj.

  • dreamy
    real, horrible, unromantic, terrible.
  • empty
    worthwhile, meaningful, complete, entire, filled, fruitful, replete, sated, valuable, full, useful, productive, abundant, sufficient, effective, raised, copious, satisfied.
  • ethereal
    indelicate, earthly, worldly, poor.
  • flimsy
    tough, serious, convincing, efficient, plausible, able, sound, healthy, firm, sturdy, strong, heavy, substantial, thick, solid, reasonable.
  • floating
    sunk, submerged.
  • frail
    hearty, fat, unbreakable, rough.
  • futile
    hopeful, helpful, successful, profitable.
  • illogical
    logical, wise, sensible, rational, correct, right, true.
  • imaginary
    factual, proven, physical, genuine, existing, ordinary, practical.
  • immaterial
    relevant, important, essential, bodily, material.
  • implausible
    possibly, probably, realistic, tenable, credible, believable, possible, likely.
  • improbable
    probable, ostensible.
  • inconceivable
    conceivable, Familiar, normal, fathomable, common, imaginable, usual.
  • incredible
    bad.
  • infirm
    robust.
  • insignificant
    major, big, huge, consequential, significant, large.
  • intangible
    tangible, palpable, obvious, definite, perceptible.
  • less
    superior, higher, greater, bigger, more.
  • light
    obscure, coarse, dark, clumsy, black, violent, dusky, loud, bold, laborious, great, grave, dim, weighted, gloomy, oppressive, strict, darkened, harsh, wild, solemn, brave, difficult, brunette, concentrated.
  • limp
    Energized, refreshed, active, hard, inflexible, invigorated, saved, stiff, unbending, lively, tight, restored, activated, taut, fresh, rigid, animated, straight.
  • metaphysical
    objective, concrete.
  • nonexistent
    existent, actual.
  • pale
    smart, distinct, intelligent, light, colored, happy, glowing, clear, radiant, colorful, flushed, bright.
  • puny
    giant.
  • sleazy
    respectable, nice, good, fine, reputable.
  • thick
    uncrowded, unfriendly, unsociable, watery, diluted, attenuated, slight, loose.
  • thin
    undiluted, inflated, dense, adequate, obese.
  • unreal
    authentic.
  • unsound
    well, safe, balanced, certain, protected, accurate, secure, just, honest, steady, stable, perfect, sure, valid, sane, reliable.
  • unsubstantial
    well-founded, undeniable.
  • weak
    noisy, powerful, capable, fit, potent, confident, competent, enough, unwavering, unshaky, guarded.
  • wrong
    appropriate, ok, precise, decent, acceptable, moral, suitable.