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 (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
- 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.
In Sergei Loznitsa’s new drama, stairwells are sinister.
From Los Angeles Times • Mar. 26, 2026
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
“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
He also accused Iran of "pursuing sinister nuclear ambitions", though Tehran has always insisted its programme is for civilian purposes.
From Barron's • Feb. 27, 2026
Some even caught glimpses of his sinuous form, silhouetted against the light-colored stone of which Rome was built, a sinister shadow sliding past walls and closed gates.
From "Tiger, Tiger" by Lynne Reid Banks
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.
