[ sin-uh-ster ]
See synonyms for sinister on
  1. threatening or portending evil, harm, or trouble; ominous: a sinister remark.

  2. bad, evil, base, or wicked; fell: his sinister purposes.

  1. unfortunate; disastrous; unfavorable: a sinister accident.

  2. of or on the left side; left.

  3. Heraldry. noting the side of an escutcheon or achievement of arms that is to the left of the bearer (opposed to dexter).

Origin of sinister

First recorded in 1375–1425; late Middle English, from Latin: “on the left hand or side,” hence, “unfavorable, injurious”

Other words for sinister

Opposites for sinister

Other words from sinister

  • sin·is·ter·ly, adverb
  • sin·is·ter·ness, noun
  • un·sin·is·ter, adjective
  • un·sin·is·ter·ly, adverb
  • un·sin·is·ter·ness, noun Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

British Dictionary definitions for sinister


/ (ˈsɪnɪstə) /

  1. threatening or suggesting evil or harm; ominous: a sinister glance

  2. evil or treacherous, esp in a mysterious way

  1. (usually postpositive) heraldry of, on, or starting from the left side from the bearer's point of view and therefore on the spectator's right

  2. archaic located on the left side

  3. archaic (of signs, omens, etc) unfavourable

Origin of sinister

C15: from Latin sinister on the left-hand side, considered by Roman augurs to be the unlucky one

Derived forms of sinister

  • sinisterly, adverb
  • sinisterness, 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