doubtful

1 of 2

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

doubtfulness

2 of 2

noun

doubt·​ful·​ness

-fəlnə̇s

plural -es

: the quality or state of being doubtful : uncertainty

Synonyms of doubtful

Adjective

• 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

Adjective

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

Adjective

Bell, who was listed as doubtful, has appeared in all six games this season, recording 10 tackles. — Matt Murschel, The Orlando Sentinel, 22 Oct. 2026

Sixth-year player Landon Walker got most of the carries in Payne’s absence, but he’s listed as doubtful for Saturday against West Virginia. — Steven Johnson, Fort Worth Star-Telegram, 22 Oct. 2026

Whether growth alone can actually solve the federal debt is doubtful. — Marco Quiroz-Gutierrez, Fortune, 16 Oct. 2026

Both stocks have rallied in 2026, with Dell up more than 350% and HPE soaring 185%, but analysts at the bank are doubtful the gains can be sustained much longer. — Davis Giangiulio,darla Mercado, Cfp®, CNBC, 14 Oct. 2026

Word History

Etymology

Adjective

see doubt entry 1

First Known Use

Adjective

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