Synonyms of dubious

dubious

adjective

ˈdü-bē-əs 

1

as in questionable

giving good reason for being doubted, questioned, or challenged

any letter bearing the signature of Geronimo would be of dubious authenticity, to say the least

Synonyms & Similar Words

• questionable
• disputable
• suspicious
• doubtful
• problematic
• debatable
• suspect
• shaky
• ambiguous
• fishy
• alleged
• equivocal
• dodgy
• shady
• queer
• unclear
• dubitable
• doubtable
• unlikely
• uncertain
• weak
• moot
• supposed
• improbable
• undetermined
• flimsy
• so-called
• undecided
• far-fetched
• open

Antonyms & Near Antonyms

• certain
• indisputable
• unquestionable
• sure
• undeniable
• undoubted
• indubitable
• incontestable
• unproblematic
• decisive
• definitive
• obvious
• questionless
• positive
• hands-down
• clear
• open-and-shut

2

as in reluctant

slow to begin or proceed with a course of action because of doubts or uncertainty

I'm dubious about our plan to go hang gliding without having had any training

Synonyms & Similar Words

• reluctant
• hesitant
• unsure
• unwilling
• skeptical
• loath
• uncertain
• cagey
• doubtful
• disinclined
• reticent
• indisposed
• unenthusiastic
• ambivalent
• questioning
• timid
• averse
• conflicted
• wobbly
• faltering
• irresolute
• infirm
• indecisive
• undecided
• vacillating
• halting
• uneager
• shy
• fainthearted

Antonyms & Near Antonyms

• enthusiastic
• eager
• inclined
• happy
• glad
• keen
• certain
• willing
• ready
• disposed
• decided
• sure
• determined
• resolute
• unquestioning

3

as in unlikely

not likely to be true or to occur

made the dubious claim of being of royal blood

Synonyms & Similar Words

• unlikely
• questionable
• doubtful
• improbable
• odd
• flimsy
• bizarre
• far-fetched
• impossible
• incredible
• implausible
• unapt
• ridiculous
• unbelievable
• inconceivable
• absurd
• unimaginable
• unthinkable
• fantastic
• nonsensical
• foolish
• outlandish
• preposterous
• insane
• unreal
• crazy
• slight
• outside
• remote
• wild

Antonyms & Near Antonyms

• probable
• likely
• plausible
• possible
• credible
• potential
• conceivable
• earthly
• believable
• imaginable
• liable

4

as in skeptical

not feeling sure about the truth, wisdom, or trustworthiness of someone or something

dubious about a diet that claims I can eat all I want and still lose weight

Synonyms & Similar Words

• skeptical
• unsure
• suspicious
• uncertain
• doubtful
• unsettled
• unconvinced
• distrustful
• mistrustful
• undecided
• ambivalent
• on the fence
• hesitant
• trustless
• hinky
• conflicted
• equivocal
• diffident
• insecure
• irresolute
• indecisive
• halting
• vacillating
• wavering

Antonyms & Near Antonyms

• certain
• positive
• sure
• convinced
• confident
• assured
• sanguine
• decisive
• determined
• resolute
• self-assured

Synonym Chooser

How does the adjective dubious contrast with its synonyms?

Some common synonyms of dubious are doubtful, problematic, and questionable. While all these words mean "not affording assurance of the worth, soundness, or certainty of something," dubious stresses suspicion, mistrust, or hesitation.

dubious about the practicality of the scheme

When would doubtful be a good substitute for dubious?

The meanings of doubtful and dubious largely overlap; however, doubtful implies little more than a lack of conviction or certainty.

doubtful about whether I said the right thing

Where would problematic be a reasonable alternative to dubious?

While in some cases nearly identical to dubious, problematic applies especially to things whose existence, meaning, fulfillment, or realization is highly uncertain.

whether the project will ever be finished is problematic

When could questionable be used to replace dubious?

The words questionable and dubious can be used in similar contexts, but questionable may imply no more than the existence of doubt but usually suggests that the suspicions are well-grounded.

a man of questionable honesty

Example Sentences

Recent Examples of dubious

Discussions about limiting Iran’s nuclear program are formidably complex, with challenges that are both technical (determining the speeds of centrifuges that can be used) and diplomatic (verifying the Iranians’ often dubious claims of disarmament). — Dexter Filkins, New Yorker, 14 Sep. 2026

The sleek, gold-colored coupé impressed with a futuristic design, but baffled onlookers with its cramped two-seat interior, lack of a charging port, and a dubious, far-too-good-to-be-true $30,000 price tag. — Victor Tangermann, Futurism, 10 Sep. 2026

For years, collectors endured reissues of varying dubious quality, including some even cut at the wrong speed. — Brian McCollum, Freep.com, 10 Sep. 2026

Another online retelling from a dubious source cited in Wikipedia even puts him in Oklahoma. — Bud Kennedy, Fort Worth Star-Telegram, 9 Sep. 2026