[ om-uh-nuhs ]
See synonyms for ominous on
  1. portending evil or harm; foreboding; threatening; inauspicious: an ominous bank of dark clouds.

  2. indicating the nature of a future event, for good or evil; having the significance of an omen; being a portent: Some of these events were immediately ominous, while others only later revealed themselves as such.

Origin of ominous

First recorded in 1580–90; from Latin ōminōsus “portentous,” equivalent to ōmin- (stem of ōmen ) + -ōsus; see origin at omen, -ous

synonym study For ominous

Ominous, portentous, threatening, menacing, fateful are adjectives describing that which forebodes a serious, significant, and often harmful outcome. Ominous, derived from omen “a predictor of outcomes,” usually suggests evil or damaging eventualities: ominous storm clouds; an ominous silence. Portentous, although it may suggest evil results, often stresses a momentous or very important outcome: a portentous moment in history; a portentous escalation of hostilities. Threatening may suggest calamity or great harm but sometimes mere unpleasantness: a threatening rumble from the volcano; A threatening look from his brother caused him to quickly change the subject. Menacing always suggests serious damage as an outcome: He advanced with a menacing swagger. Fateful most often stresses the great or decisive importance of what it describes: a fateful encounter between two future leaders; a fateful day that changed our world.

Other words from ominous

  • om·i·nous·ly, adverb
  • om·i·nous·ness, noun
  • un·om·i·nous, adjective
  • un·om·i·nous·ly, adverb
  • un·om·i·nous·ness, noun

Words Nearby ominous Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use ominous in a sentence

British Dictionary definitions for ominous


/ (ˈɒmɪnəs) /

  1. foreboding evil

  2. serving as or having significance as an omen

Origin of ominous

C16: from Latin ōminōsus, from omen

Derived forms of ominous

  • ominously, adverb
  • ominousness, 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