Synonyms of doubtful

doubtful

adjective

ˈdau̇t-fəl 

1

as in unsure

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

he was doubtful about the decision to complete the project despite its mounting problems

Synonyms & Similar Words

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

Antonyms & Near Antonyms

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

2

as in questionable

giving good reason for being doubted, questioned, or challenged

the election results were highly doubtful, so an investigation was begun

Synonyms & Similar Words

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

Antonyms & Near Antonyms

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

3

as in unlikely

not likely to be true or to occur

our winning the championship increasingly looks like a doubtful outcome

Synonyms & Similar Words

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

Antonyms & Near Antonyms

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

4

as in disputable

open to question or dispute

a doubtful claim to the property

Synonyms & Similar Words

• questionable
• disputable
• debatable
• arguable
• moot
• disputed
• controversial
• negotiable
• ambiguous
• uncertain
• controvertible
• doubtable
• issuable
• debated
• speculative
• problematic
• iffy
• inconclusive
• hypothetical
• dubious
• shaky
• theoretical
• refutable
• indecisive
• contradictable
• equivocal
• academic

Antonyms & Near Antonyms

• sure
• certain
• positive
• unquestionable
• indisputable
• undeniable
• unanswerable
• indubitable
• incontestable
• accomplished
• incontrovertible
• settled
• irrefragable
• unchallengeable
• unarguable
• definite
• irrefutable
• undebatable
• inarguable
• unequivocal
• questionless
• conclusive
• unambiguous
• decisive
• clear
• hands-down
• absolute
• undisputed
• uncontested

Synonym Chooser

How does the adjective doubtful contrast with its synonyms?

Some common synonyms of doubtful are dubious, problematic, and questionable. While all these words mean "not affording assurance of the worth, soundness, or certainty of something," doubtful implies little more than a lack of conviction or certainty.

doubtful about whether I said the right thing

When is dubious a more appropriate choice than doubtful?

The words dubious and doubtful are synonyms, but do differ in nuance. Specifically, dubious stresses suspicion, mistrust, or hesitation.

dubious about the practicality of the scheme

When is it sensible to use problematic instead of doubtful?

While the synonyms problematic and doubtful are close in meaning, problematic applies especially to things whose existence, meaning, fulfillment, or realization is highly uncertain.

whether the project will ever be finished is problematic

When would questionable be a good substitute for doubtful?

While in some cases nearly identical to doubtful, 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 doubtful

Surveying the field, Morrisson is doubtful there's a candidate who can top Biss - especially a challenger running further to the left. —Elena Moore, NPR, 15 Mar. 2026

When recovery becomes doubtful or diminished, incentives weaken. —Ascend Agency, Chicago Tribune, 12 Mar. 2026

No one in Málaga sounded doubtful about Spain’s talent base. —Emiliano De Pablos, Variety, 11 Mar. 2026

Smart, who has been the cornerstone of the Lakers’ defensive operation in recent weeks, is doubtful for Thursday’s game against the Bulls with a right hip contusion. —Benjamin Royer, Oc Register, 11 Mar. 2026