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Synonyms

sinister

American  
[sin-uh-ster] / ˈsɪn ə stər /

adjective

  1. threatening or portending evil, harm, or trouble; ominous.

    a sinister remark.

    Synonyms:
    portentous, inauspicious
    Antonyms:
    benign
  2. bad, evil, base, or wicked; fell.

    his sinister purposes.

  3. unfortunate; disastrous; unfavorable.

    a sinister accident.

    Synonyms:
    unlucky
    Antonyms:
    favorable
  4. of or on the left side; left.

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


sinister British  
/ ˈsɪnɪstə /

adjective

  1. threatening or suggesting evil or harm; ominous

    a sinister glance

  2. evil or treacherous, esp in a mysterious way

  3. (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

  4. archaic located on the left side

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

"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

Other Word Forms

  • sinisterly adverb
  • sinisterness noun
  • unsinister adjective
  • unsinisterly adverb
  • unsinisterness noun

Etymology

Origin of sinister

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

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

The movie’s real draw is its blissfully sinister sound design, which utilizes the podcaster lifestyle to go full maximalist while the film’s visual landscape remains sparse and disquieting.

From Salon • Mar. 15, 2026

A more sinister figure lurks behind Rodriguez in interior and justice minister Diosdado Cabello, Pachon notes.

From Barron's • Mar. 12, 2026

“We would interpret the correction signal activation as warning of a potential further short-term correction in the S&P 500 to test the 200-day moving average support, rather than anything more sinister for now.”

From MarketWatch • Mar. 5, 2026

Miriam is vivacious and energetic but dogged by an unexplained sin from her earlier life—a sin that vests itself in the sinister person of her “model.”

From The Wall Street Journal • Feb. 27, 2026

Afterward they constructed a new face for him that gave him a sinister, ferocious appearance.

From "The Great Santini" by Pat Conroy