doubt·​ful ˈdau̇t-fəl How to pronounce doubtful (audio)
: lacking a definite opinion, conviction, or determination
They were doubtful about the advantages of the new system.
: uncertain in outcome : undecided
The outcome of the election remains doubtful.
: marked by qualities that raise doubts about worth, honesty, or validity
of doubtful repute
: giving rise to doubt or uncertainty : open to question
It is doubtful that they ever knew what happened.
a doubtful premise
doubtfully adverb
doubtfulness noun
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 The librarians were doubtful, but ultimately gave him access. Rachel Donadio, New York Times, 1 May 2024 Lewis, of the Center for Strategic and International Studies, is doubtful the latest push will result in ByteDance letting go of TikTok. Bobby Allyn, NPR, 20 Apr. 2024 See all Example Sentences for doubtful 

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'doubtful.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


see doubt entry 1

First Known Use

14th century, in the meaning defined at sense 3

Time Traveler
The first known use of doubtful was in the 14th century

Dictionary Entries Near doubtful

Cite this Entry

“Doubtful.” Dictionary, Merriam-Webster, Accessed 22 May. 2024.

Kids Definition


doubt·​ful ˈdau̇t-fəl How to pronounce doubtful (audio)
: not clear or certain as to fact
a doubtful claim
: questionable sense 2
doubtful intentions
: undecided in opinion
: not certain in outcome
doubtfully adverb
doubtfulness noun

More from Merriam-Webster on doubtful

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!