sinister
Americanadjective
-
threatening or portending evil, harm, or trouble; ominous.
a sinister remark.
- Synonyms:
- portentous, inauspicious
- Antonyms:
- benign
-
bad, evil, base, or wicked; fell.
his sinister purposes.
-
unfortunate; disastrous; unfavorable.
a sinister accident.
- Synonyms:
- unlucky
- Antonyms:
- favorable
-
of or on the left side; left.
-
Heraldry. noting the side of an escutcheon or achievement of arms that is to the left of the bearer (opposed to dexter).
adjective
-
threatening or suggesting evil or harm; ominous
a sinister glance
-
evil or treacherous, esp in a mysterious way
-
(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
-
archaic located on the left side
-
archaic (of signs, omens, etc) unfavourable
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.
Vocabulary lists containing sinister
The SAT: Words to Capture Tone, List 3
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"The Monkey's Paw" by W. W. Jacobs
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The New SAT: Words to Capture Tone
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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.
Out of loneliness, she becomes involved with her downstairs neighbor, a lovely but sinister musician.
From The Wall Street Journal ● Jul. 6, 2026
"The truth is far more sinister and darker than that."
From BBC ● Jun. 18, 2026
While Rhaenyra’s story will touch on “the more sinister side of relinquishing doubt,” D’Arcy considers that there is, perhaps, “a more positive side to that too.”
From Los Angeles Times ● Jun. 17, 2026
Phil, the dorky and faintly sinister middle-aged employee of Async, explains to Mary that his company used to make MRI machines.
From Salon ● Jun. 8, 2026
Pale, with a sinister grin and familiar blue eyes.
From "The Last Last-Day-of-Summer" by Lamar Giles
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
