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.
A more sinister figure lurks behind Rodriguez in interior and justice minister Diosdado Cabello, Pachon notes.
From Barron's • Mar. 12, 2026
His angular head topped with a green felt crown; his toothy mouth a sinister, grimacing gash; his eyes blackened with what looks like charcoal.
From Los Angeles Times • Mar. 9, 2026
This fourth problem makes the first three look like sinister, rather than innocent, bureaucratic snafus.
From Salon • Mar. 5, 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
They whimpered fearfully at the sinister sight of Cluny the Scourge.
From "Redwall" by Brian Jacques
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.
