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adjective doubt·ful \ˈdau̇t-fəl\

Simple Definition of doubtful

  • : uncertain or unsure about something

  • : not likely to be true : not probable

  • : likely to be bad : not worthy of trust

Source: Merriam-Webster's Learner's Dictionary

Full Definition of doubtful

  1. 1 :  giving rise to doubt :  open to question <it is doubtful that they ever knew what happened>

  2. 2 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>

  3. 3 :  marked by qualities that raise doubts about worth, honesty, or validity <of doubtful repute>

doubtfully play \-fə-lē\ adverb
doubtfulness noun

Examples of doubtful in a sentence

  1. I tried to reassure them, but they remained doubtful.

  2. The truth of the statements was doubtful.

  3. Their decisions were based on data of doubtful accuracy.

14th Century

First Known Use of doubtful

14th century

Synonym Discussion of 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>.

DOUBTFUL Defined for Kids


adjective doubt·ful \ˈdau̇t-fəl\

Definition of doubtful for Students

  1. 1 :  undecided or unsure about something <I'm doubtful we'll make it on time.> <Minli was a little doubtful about riding the dragon. — Grace Lin, Where the Mountain Meets the Moon>

  2. 2 :  not likely to be true <a doubtful claim>

  3. 3 :  not likely to be good <doubtful quality>

  4. 4 :  not certain in outcome <a doubtful future>

doubtfully \-fə-lē\ adverb

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