Definitions

sinister

[sin-uh-ster] / ˈsɪn ə stər /

ADJECTIVE

nasty, menacing

Synonyms

STRONGEST

dire evil malevolent mischievous ominous perverse threatening

WEAK

adverse apocalyptic bad baleful baneful blackhearted corrupt deleterious disastrous dishonest disquieting doomful foreboding harmful hurtful ill-boding inauspicious injurious lowering malefic malign malignant obnoxious pernicious poisonous portentous unfavorable unfortunate unlucky unpropitious woeful

Antonyms

STRONGEST

auspicious good lucky nice

WEAK

benevolent kind

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.

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

From Barron's • May 5, 2026

For neurologist Taka, not his real name, the delusions took an even more sinister turn.

From BBC • May 2, 2026

It wasn’t just the silicone that media outlets had branded suspicious and sinister.

From Slate • Apr. 19, 2026

Critics, Alito said at the time, were falsely suggesting that the court was behaving in a sinister fashion.

From The Wall Street Journal • Apr. 18, 2026

Each one held the face of a woman wearing clown makeup and a strange, sinister smile.

From "The Marvellers" by Dhonielle Clayton

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!