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Synonyms

dubious

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

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

Derived 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."

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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.

Honestly, I’m dubious of the film’s certainty that folks even have the bandwidth to care about such news, let alone agree on what they’re seeing.

From Los Angeles Times • Jun. 10, 2026

There are morally and ethically dubious questions aplenty.

From Salon • Jun. 6, 2026

The new contracts for two ageing stars suddenly look very dubious – but this is easy to say now.

From BBC • May 30, 2026

Industry representatives say lawyers encourage homeowners to pursue dubious allegations.

From The Wall Street Journal • May 19, 2026

There might be some “right” price for insuring the first losses on pools of bonds backed by pools of dubious loans, but it wasn’t one-half of 1 percent.

From "The Big Short" by Michael Lewis

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