The DICT Development Group

  Unsubstantial \Unsubstantial\
     See substantial.

  Unsubstantial \Un`sub*stan"tial\, a.
     Lacking in matter or substance; visionary; chimerical.
     [1913 Webster]

  unsubstantial
      adj 1: lacking material form or substance; unreal; "as
             insubstantial as a dream"; "an insubstantial mirage on
             the horizon" [syn: insubstantial, unsubstantial,
             unreal] [ant: material, real, substantial]

  182 Moby Thesaurus words for "unsubstantial":
     Barmecidal, Barmecide, adulterated, airy, apparent, apparitional,
     asomatous, astral, attenuate, attenuated, autistic, bodiless,
     breakable, brittle, cheap-jack, chimeric, cobwebby, crumbling,
     crumbly, cut, dainty, dangerous, decarnate, decarnated, deceptive,
     decrepit, delicate, delicately weak, delusional, delusionary,
     delusive, delusory, dereistic, desultory, dilute, diluted,
     discarnate, disembodied, disintegrating, dreamlike, dreamy,
     effeminate, erroneous, ethereal, extramundane, fallacious, false,
     fanciful, fantastic, feeble, fine, flimsy, fragile, frail,
     frangible, gaseous, ghostly, gimcrack, gimcracky, gossamery,
     hazardous, illusional, illusionary, illusive, illusory, imaginary,
     immaterial, impalpable, imponderable, improbable, inconceivable,
     inconclusive, incorporate, incorporeal, incredible, infirm,
     insecure, insubstantial, intangible, jerry, jerry-built, light,
     lightweight, merely nominal, metaphysical, misleading, namby-pamby,
     nonmaterial, nonphysical, nonsubstantial, not real, occult,
     ostensible, otherworldly, papery, pasteboardy, perilous,
     phantasmagoric, phantasmal, phantom, poor, poorish, precarious,
     provisional, psychic, puny, rare, rarefied, risky, rotten,
     rotten at, seeming, self-deceptive, self-deluding, shadowy, shaky,
     shattery, shifting, shifty, sissified, sleazy, slight, slippery,
     specious, spectral, spiritual, subtile, subtle, supernatural,
     supposititious, tacky, temporary, tentative, tenuous, thick, thin,
     thinned, thinned-out, ticklish, transmundane, treacherous,
     unactual, unbelievable, uncompact, uncompressed, unconcrete,
     unconvincing, undependable, unearthly, unembodied, unextended,
     unfaithworthy, unfirm, unfleshly, unfounded, unphysical, unproved,
     unreal, unrealistic, unreliable, unrigorous, unsolid, unsound,
     unstable, unsteadfast, unsteady, unsturdy, unsubstanced, unsure,
     unsustained, untrustworthy, unworldly, vaporous, visionary,
     watered, watered-down, weak, weakly, weightless, windy, wispy,
     womanish