doubtful

adjective

doubt·​ful ˈdau̇t-fəl 

1

a

: lacking a definite opinion, conviction, or determination

They were doubtful about the advantages of the new system.

b

: uncertain in outcome : undecided

The outcome of the election remains doubtful.

2

: marked by qualities that raise doubts about worth, honesty, or validity

of doubtful repute

3

: giving rise to doubt or uncertainty : open to question

It is doubtful that they ever knew what happened.

a doubtful premise

doubtfully

ˈdau̇t-fə-lē 

adverb

doubtfulness noun

Synonyms

• unsure
• skeptical
• suspicious
• uncertain

Choose the Right Synonym for doubtful

doubtful, dubious, problematic, questionable 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

dubious stresses suspicion, mistrust, or hesitation.

dubious about the practicality of the scheme

problematic applies especially to things whose existence, meaning, fulfillment, or realization is highly uncertain.

whether the project will ever be finished is problematic

questionable may imply no more than the existence of doubt but usually suggests that the suspicions are well-grounded.

a man of questionable honesty

Examples of doubtful in a Sentence

I tried to reassure them, but they remained doubtful.

The truth of the statements was doubtful.

Their decisions were based on data of doubtful accuracy.

Recent Examples on the Web

After delivering several flops since its inception in 2019, such as Napoleon and Killers of the Flower Moon, the future of Apple's foray into movies remained doubtful. —Saajan Jogia, MSNBC Newsweek, 2 July 2025

Ticketing companies show support for Donald Trump's executive order, others prove to be doubtful of 'meaningful change' Live Nation, parent company of Ticketmaster, issued a statement supporting Trump's executive order and calling for a cap on resale prices. —Diana Leyva, The Tennessean, 2 July 2025

The bill is doubtful to get support from any Senate Democrat, but under special Senate rules, only 51 Republicans are needed to sign-off and avoid a filibuster. —Savannah Kuchar, USA Today, 28 June 2025

Whether Afshar could have solved this is highly doubtful, since the problem rests heavily with Musk’s own decisions. —Christiaan Hetzner, Fortune, 27 June 2025

Word History

Etymology

see doubt entry 1

First Known Use

14th century, in the meaning defined at sense 3

Kids Definition

doubtful

adjective

doubt·​ful ˈdau̇t-fəl 

1

: not clear or certain as to fact

a doubtful claim

2

: questionable sense 2

doubtful intentions

3

: undecided in opinion

4

: not certain in outcome

doubtfully

-fə-lē 

adverb

doubtfulness noun