Mawson, C.O.S., ed. (1870–1938). Roget’s International Thesaurus. 1922.

Class I. Words Expressing Abstract Relations
Section I. Existence
2. Being, in the Concrete

4. Unsubstantiality.

   NOUN:UNSUBSTANTIALITY, insubstantiality; nothingness, nihility; no degree, no part, no quantity, no thing.
  NOTHING, naught, nil [L.], nullity. zero, cipher, no one, nobody; never a one, ne’er one; no such thing, none in the world; nothing whatever, nothing at all, nothing on earth; not a particle (smallness) [See Smallness]; all talk, all moonshine, all stuff and nonsense; matter of no importance, matter of no consequence.
  THING OF NAUGHT, man of straw, John Doe and Richard Roe, fagot (or faggot) voter [polit. cant, Eng.]; nominis umbra [L.], nonentity, cipher, nought, nothing, obscurity, lay figure; flash in the pan, vox et præterea nihil [L.].
  PHANTOM (fallacy of vision) [See Dim-sightedness]; shadow; dream (imagination) [See Imagination]; ignis fatuus [L.] (luminary) [See Luminary]; “such stuff as dreams are made on” [Tempest]; air, thin air; bubble [See Bubble, Cloud]; mockery.
  BLANK; void (absence) [See Absence]; hollowness.
  INANITY, fatuity, fool’s paradise.
   VERB:VANISH, evaporate, fade, fleet, sink, fly, dissolve, melt away; die, die away, die out; disappear [See Disappearance].
   ADJECTIVE:UNSUBSTANTIAL; baseless, groundless; ungrounded; without foundation, having no foundation.
  VISIONARY (imaginary) [See Imagination]; immaterial [See Infrequency]; spectral [See Evil Spirits]; dreamy; shadowy; ethereal, airy, gaseous, imponderable, tenuous, vague, vaporous, dreamlike, mushroom; cloud-built, cloud-formed; gossamery, illusory, insubstantial, unreal, unsolid [rare], slight, bodiless.
  VACANT, vacuous; empty [See Absence]; eviscerated; blank, hollow; nominal; null; inane [rare].
  1. There’s nothing in it.
  2. An ocean of dreams without a sound.—Shelley
  3. The baseless fabric of this vision.—Tempest
  4. This bodiless creation ecstasy Is very cunning in.—Hamlet