Thesaurus.com
Dictionary.com
Definitions

dubious

[doo-bee-uhs, dyoo-] / ˈdu bi əs, ˈdyu- /
ADJECTIVE
doubtful
Synonyms
STRONGEST
arguable debatable equivocal fishy hesitant improbable problematic questionable reluctant shady skeptical suspicious uncertain unclear unconvinced unreliable unsure
WEAK
chancy diffident disputable dubitable far-fetched fly-by-night iffy indecisive moot mootable open perplexed suspect touch and go trustless unassured undecided undependable unlikely untrustworthy untrusty wavering
Antonyms
STRONGEST
aboveboard believable certain clear definite determined honest indubious likely probable secure sure trustworthy undoubted unquestionable
WEAK
doubtless positive reliable trusty unambiguous undoubtful unobscure
ADJECTIVE
vague, unclear
Synonyms
STRONGEST
ambiguous debatable doubtful equivocal problematic
WEAK
disinclined indefinite indeterminate mistrustful obscure open problematical undecided unsettled
Antonyms
STRONGEST
certain clear definite settled sure unquestionable
WEAK
doubtless positive reliable trustworthy trusty unambiguous undoubtful unobscure

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.

They’re at the root of my being dubious of the simple and easy.

From Salon • Apr. 13, 2026

But that would sever the subways’ supply of capital and its revenue—a dubious fix.

From The Wall Street Journal • Apr. 10, 2026

The deployments have made Iranian diplomatic envoys even more dubious that American peace efforts are sincere.

From Los Angeles Times • Mar. 30, 2026

The part where the laser guides the VSELs around Scott’s body is perhaps the most dubious of a procedure littered with doubt.

From Slate • Mar. 30, 2026

He gave his head a little dubious shake, as if disowning responsibility for what he was about to tell me.

From "A Walk in the Woods" by Bill Bryson

Vocabulary lists containing dubious

The SAT: Words to Capture Tone, List 2

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!

Lord of the Flies

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!