[uhn-suh b-stan-shuh l]
See more synonyms for unsubstantial on Thesaurus.com
  1. not substantial; having no foundation in fact; fanciful; insubstantial: an unsubstantial argument; unsubstantial hopes.
  2. without material substance: an unsubstantial ghost.
  3. lacking material substance; materially paltry: an unsubstantial dinner of bread and cheese.
  4. lacking strength or solidity; flimsy: an unsubstantial wall of cardboard.

Origin of unsubstantial

late Middle English word dating back to 1425–75; see origin at un-1, substantial
Related formsun·sub·stan·ti·al·i·ty, nounun·sub·stan·tial·ly, adverb
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for unsubstantial

Contemporary Examples of unsubstantial

Historical Examples of unsubstantial

  • Within a minute afterwards, he was, to all outward appearance, as unsubstantial as ever.

    A Tale of Two Cities

    Charles Dickens

  • Were I a fat man I could not bear it, but I am as unsubstantial as they themselves.

  • Scott, in Old Mortality, uses it in the moral sense, "unsubstantial."

    The Proverbs of Scotland

    Alexander Hislop

  • No darkness of the sky, or concentration of unsubstantial vapour.

    The Death Shot

    Mayne Reid

  • That was why the glories were so unsubstantial, and why the dream must end at midnight.

    A Modern Cinderella

    Amanda M. Douglas

British Dictionary definitions for unsubstantial


  1. lacking weight, strength, or firmness
  2. (esp of an argument) of doubtful validity
  3. of no material existence or substance; unreal
Derived Formsunsubstantiality, noununsubstantially, adverb
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for unsubstantial

mid-15c., from un- (1) "not" + substantial.

Online Etymology Dictionary, © 2010 Douglas Harper