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 of doubtful

• 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

Public approval is doubtful as New Yorkers ratified this structure in 2014 and rejected an attempt to change it in 2021. —New York Daily News Editorial Board, New York Daily News, 4 June 2026

There is some irony in that Donachie also coaches Barcelona’s Manchester United loanee Marcus Rashford, for whom a permanent move to the Camp Nou now looks doubtful after his England team-mate’s arrival. —Patrick Boyland, New York Times, 2 June 2026

McClure, of course, would love to see Steyer take the top spot in that easy-win scenario against Hilton, though that seems doubtful. —Los Angeles Times, 30 May 2026

That goal looks especially doubtful now. —Michael Kan, PC Magazine, 29 May 2026

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