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
Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!
"The Monkey's Paw" by W. W. Jacobs
Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!
The New SAT: Words to Capture Tone
Want to remember this word for good? Start your learning journey today with our library of interactive, themed word lists built by the experts at Vocabulary.com – we'll help you make the most of your study time!
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
![]()
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.