[ dout-fuhl ]
See synonyms for: doubtfuldoubtfullydoubtfulness on

  1. of uncertain outcome or result.

  2. admitting of or causing doubt; uncertain; ambiguous.

  1. unsettled in opinion or belief; undecided; hesitating.

  2. of equivocal or questionable character: His tactics are highly doubtful.

Origin of doubtful

First recorded in 1350–1400, doubtful is from the Middle English word douteful.See doubt, -ful

synonym study For doubtful

3. Doubtful, dubious, incredulous, skeptical imply reluctance or unwillingness to be convinced. To be doubtful about something is to feel that it is open to question or that more evidence is needed to prove it: to be doubtful about the statements of witnesses. Dubious implies vacillation, unsureness, or suspicion: dubious about suggested methods of manufacture. Incredulous means unwilling or reluctant to believe: incredulous at the good news. Skeptical implies a general disposition to doubt or question: skeptical of human progress.

usage note For doubtful

See doubt.

Other words for doubtful

Opposites for doubtful

Other words from doubtful

  • doubt·ful·ly, adverb
  • doubt·ful·ness, noun
  • pre·doubt·ful, adjective
  • pre·doubt·ful·ly, adverb
  • quasi-doubtful, adjective
  • qua·si-doubt·ful·ly, adverb
  • un·doubt·ful, adjective
  • un·doubt·ful·ly, adverb
  • un·doubt·ful·ness, noun Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024

How to use doubtful in a sentence

British Dictionary definitions for doubtful


/ (ˈdaʊtfʊl) /

  1. unlikely; improbable

  2. characterized by or causing doubt; uncertain: a doubtful answer

  1. unsettled; unresolved

  2. of questionable reputation or morality

  3. having reservations or misgivings

  4. (of a sportsperson) not likely to be fit enough to play or take part

  1. a person who is undecided or uncertain about an issue

  2. a sportsperson who is not likely to be fit enough to play or take part

usage For doubtful

It was formerly considered correct to use whether after doubtful (it is doubtful whether he will come), but now if and that are also acceptable

Derived forms of doubtful

  • doubtfully, adverb
  • doubtfulness, noun

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012