resulting from or showing a lack of sense; ill-considered; unwise: a foolish action, a foolish speech.
lacking forethought or caution.
trifling, insignificant, or paltry.

Origin of foolish

First recorded in 1250–1300, foolish is from the Middle English word folish, foolish. See fool1, -ish1
Related formsfool·ish·ly, adverbfool·ish·ness, nouno·ver·fool·ish, adjectiveo·ver·fool·ish·ly, adverbo·ver·fool·ish·ness, nounqua·si-fool·ish, adjectivequa·si-fool·ish·ly, adverbun·fool·ish, adjectiveun·fool·ish·ly, adverbun·fool·ish·ness, noun

Synonyms for foolish

1, 2. senseless, vacant, vapid, simple, witless. Foolish, fatuous, silly, inane, stupid, asinine imply weakness of intellect and lack of judgment. Foolish implies lack of common sense or good judgment or, sometimes, weakness of mind: a foolish decision; The child seems foolish. Fatuous implies being not only foolish, dull, and vacant in mind, but complacent and highly self-satisfied as well: fatuous and self-important; fatuous answers. Silly denotes extreme and conspicuous foolishness; it may also refer to pointlessness of jokes, remarks, etc.: silly and senseless behavior; a perfectly silly statement. Inane applies to silliness that is notably lacking in content, sense, or point: inane questions that leave one no reply. Stupid implies natural slowness or dullness of intellect, or, sometimes, a benumbed or dazed state of mind; it is also used to mean foolish or silly: well-meaning but stupid; rendered stupid by a blow; It is stupid to do such a thing. Asinine originally meant like an ass; it applies to witlessly stupid conversation or conduct and suggests a lack of social grace or perception: He failed to notice the reaction to his asinine remarks. 1. imprudent, unreasonable, foolhardy, irrational; thoughtless, nonsensical, ridiculous, absurd, pointless, preposterous. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for foolishness

Contemporary Examples of foolishness

Historical Examples of foolishness

  • His long habit of thought concerning her enabled him to master this foolishness.

    The Spenders

    Harry Leon Wilson

  • We must protect her from the consequences of her own foolishness.

  • It just came over me, all at once, that I—It was just foolishness.


    Mary Roberts Rinehart

  • I didn't enter him; that was somebody else's foolishness, and I don't want to back him.


    W. A. Fraser

  • "Don't ye be lettin' yourself belave your own foolishness," she said.

    Her Father's Daughter

    Gene Stratton-Porter

British Dictionary definitions for foolishness



unwise; silly
resulting from folly or stupidity
ridiculous or absurd; not worthy of consideration
weak-minded; simple
an archaic word for insignificant
Derived Formsfoolishly, adverbfoolishness, noun
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 foolishness



early 14c., from fool (n.) + -ish. Related: Foolishly; foolishness. Old English words for this were dysig, stunt, dol.

Online Etymology Dictionary, © 2010 Douglas Harper

Idioms and Phrases with foolishness


see penny wise and pound foolish.

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.