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.

The idea “was to create a sinister feeling that this may not end well,” he says.

From Los Angeles Times • Jun. 10, 2026

Felix Salmon, Elizabeth Spiers, and Emily Peck, discuss theories on why the hell anyone would do this and whether it’s just weird or actually sinister.

From Slate • May 23, 2026

Increasingly a sinister hue attaches to Beijing’s preference for “open weight” models.

From The Wall Street Journal • May 19, 2026

But the larger context of the Make Heaven Crowded tour exposes a sinister element of manipulation at play.

From Salon • May 17, 2026

Gradually, the graying light threw the path into shadow, and the pleasant magical creatures around him began to take on a more sinister appearance.

From "Half Upon a Time" by James Riley

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!