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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 (opposed to 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

Etymology

Origin of sinister

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

Explanation

People who are left-handed might feel unlucky having to use a desk designed for right-handers, but there probably wasn't any sinister, or evil, intent behind the design. Or was there? In the 15th century, when the word sinister came into use in English, people who were left-handed were thought to be bad luck or even evil. In his play Hamlet, Shakespeare wrote of the villain holding a human skull in his sinister — i.e., left — hand. It would seem to be sinister, or wicked, enough to see a human skull in the right hand, not to mention unlucky for the person missing a head in the first place.

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Vocabulary lists containing sinister

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 original’s Cylons were the show’s answer to George Lucas’ stormtroopers in “Star Wars,” only shinier, with sinister red lights roving back and forth where their eyes should be.

From Salon • May 5, 2026

But the picture-postcard views mask a more sinister reality.

From Barron's • May 5, 2026

Bourzgui’s David has all the hallmarks of a rock idol — sultry looks, a sinister smile and talent to burn.

From Los Angeles Times • May 1, 2026

"The evidence gathered during the investigation into his untimely death revealed a much more sinister pathology," he said.

From BBC • Apr. 20, 2026

It was not the stranded ship that was sinister, nor the crying gulls, nor the thin black funnel pointing to the shore.

From "Rebecca" by Daphne du Maurier

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