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Showing results for doubtful. Search instead for doubtfu.
Definitions

doubtful

[dout-fuhl] / ˈdaʊt fəl /
ADJECTIVE
questionable, unclear
Synonyms
STRONGEST
debatable dicey dubious hazy indecisive insecure precarious problematic suspicious uncertain undecided uneasy unsettled unstable unsure
WEAK
ambiguous borderline chancy clouded contingent disreputable doubtable dubitable equivocal far-fetched fat chance fishy hazardous iffy impugnable inconclusive indefinite indeterminate indistinct long shot obscure on thin ice open pending shady sneaky speculative suspect touch-and-go touchy unconfirmed up for grabs
Antonyms
STRONGEST
certain clear decided definite determined indubious safe secure settled stable strong sure trustworthy trusty undoubted
WEAK
believing confirmed convinced exact resolved trusting unquestionable
ADJECTIVE
not believing
Synonyms
STRONGEST
dubious hesitant indecisive puzzled skeptical suspicious tentative uncertain unconvinced undecided unsettled unsure
WEAK
agnostic baffled confused discomposed disconcerted distracted distrustful disturbed doubting equivocal faithless faltering flustered hesitating in a quandary in clouds in dilemma irresolute like doubting Thomas lost not following of two minds perplexed questioning theoretical troubled unresolved vacillating wavering without belief
Antonyms
STRONGEST
certain clear decided decisive definite determined secure settled sure trustworthy trusty undoubted
WEAK
believing confident confirmed convinced exact resolved trusting unquestionable

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.

Crude futures rose as the market remained doubtful about U.S. efforts to negotiate an end to the conflict with Iran.

From The Wall Street Journal • Mar. 27, 2026

It’s doubtful AI will flop as spectacularly as the metaverse did, if only because so many companies, universities, and governments are so vested in its success.

From Barron's • Mar. 19, 2026

Treasury yield curve would steepen through 2026, widely accepted by a net 80% of respondents in February, is now more doubtful with only 56% viewing that as likely now.

From MarketWatch • Mar. 17, 2026

It is very doubtful that, even if they somehow captured Tehran, Kurds could hold on to power for long.

From Slate • Mar. 6, 2026

Millions were still unemployed, doubtful about ever finding work again.

From "Spooked!" by Gail Jarrow

From Roget's 21st Century Thesaurus, Third Edition Copyright © 2013 by the Philip Lief Group.