Dictionary.com
Thesaurus.com
Synonyms

dubious

American  
[doo-bee-uhs, dyoo-] / ˈdu bi əs, ˈdju- /

adjective

  1. doubtful; marked by or occasioning doubt.

    a dubious reply.

    Synonyms:
    unclear, obscure, ambiguous, equivocal
  2. of doubtful quality or propriety; questionable.

    a dubious compliment; a dubious transaction.

  3. of uncertain outcome.

    in dubious battle.

  4. wavering or hesitating in opinion; inclined to doubt.

    Synonyms:
    hesitant, uncertain, undecided

dubious British  
/ ˈdjuːbɪəs /

adjective

  1. marked by or causing doubt

    a dubious reply

  2. unsettled in mind; uncertain; doubtful

  3. of doubtful quality; untrustworthy

    a dubious reputation

  4. not certain in outcome

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Synonym Usage

See doubtful.

Other Word Forms

Etymology

Origin of dubious

First recorded in 1540–50; from Latin dubius; cf. doubt ( def. )

Explanation

Choose the adjective dubious for something you have doubts about or you suspect is not true. That bridge you just "bought" might be of dubious value. Dubious stems from Latin dubiosus, "doubtful" or "uncertain," and contains the Latin root duo in this case meaning "of two minds." This is apparent in that dubious generally describes something that appears one way but is truly another. A dubious claim is probably not true, whereas a dubious website or character is of questionable quality. Dubious can also be synonymous with doubtful, as in "she was dubious about the idea."

Keep Reading on Vocabulary.com

Vocabulary lists containing dubious

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.

See Examples For:

It "cannot keep going on" with "secret schemes of fast-track timescales cooked up by faceless individuals and of dubious benefit to the game"

From BBC Aug. 1, 2026

That dubious award would go to the Venezuelan Big Mac.

From MarketWatch Jul. 31, 2026

I’m dubious about the future success of any investor, individual or professional, who reads about nothing but business.

From The Wall Street Journal Jul. 28, 2026

"Would Saudi decide to do a complete 180 on what it has declared for the past three years, or 30 years? Quite dubious," he told AFP.

From Barron's Jul. 23, 2026

“As you can imagine,” he told the cops, “I have some rather dubious clientele. What church for the poor doesn’t?”

From "I Am the Messenger" by Markus Zusak

Vocabulary.com logo
by dictionary.com

Dictionary.com's Learning Companion

Go beyond just looking up words.
Remember them forever with VocabTrainer.

Start training