adjective

dubious

/ˈduːbiəs/ · say it: DOO·bee·uhs

hesitating or doubting; questionable

In Debate & Persuasion

In more detail

1. (adjective) probably not true or not reliable; questionable

2. (adjective) not sure or confident about something; doubtful

Examples

1. The company made dubious claims about how effective their product was.
2. I'm dubious about whether that plan will actually work.

How to use dubious

Dubious is used when something appears untrustworthy, lacks convincing evidence, or when someone expresses skepticism or hesitation. It carries a stronger implication of suspicion than 'uncertain' and is more formal than 'fishy' or 'sketchy'. The two senses overlap: one describes the object as unreliable (a dubious claim), the other describes the person's attitude toward it (I'm dubious about that).

Common phrases

dubious claim
dubious quality
dubious about
cast dubious light on
dubious evidence

Synonyms

questionable · doubtful · suspect · uncertain · unreliable

Opposites

certain · reliable · credible

Word family

dubiously (adverb) · dubiousness (noun)

A common mistake

Learners sometimes use dubious when they simply mean 'unclear' or 'ambiguous'—dubious implies suspicion of falsehood or untrustworthiness, not merely lack of clarity.

Learn it for good

Save this word in WordVale and it comes back for review right before you'd forget it — with pronunciation, real examples, and optional translations. One purchase, no subscription.

Get WordValeFREE 7-DAY TRIAL · iPHONE & iPAD