mistaken

mistaken — adjective

1. believing something that is not true, or caused by such an incorrect belief

1.adjectiveB1
Definition

believing something that is not true, or caused by such an incorrect belief

Example

Adina was mistaken about the time of the meeting and arrived an hour late.

be mistaken about [topic]

Kabir's report was full of mistaken assumptions about the project budget.

attributive: a mistaken + noun

Common collocations
  • be mistaken about
  • be mistaken in
  • mistaken belief
  • mistaken impression
  • mistaken identity
  • mistaken assumption
  • if I'm not mistaken
  • sadly mistaken
Synonyms
  • wrong

    More general and neutral; 'wrong' covers factual, moral, and practical errors, while 'mistaken' specifically relates to a wrong belief.

  • incorrect

    Slightly more formal than 'mistaken', often used for factual inaccuracies rather than personal judgements.

  • misguided

    Emphasises poor judgement rather than plain error; often implies a well-intentioned but wrong course of action.

  • erroneous

    Formal and mostly written; used for data, conclusions, or official statements rather than personal beliefs.

Antonyms
  • correct

    The most direct opposite; factually right or appropriate.

  • right

    Informal and broad; opposite to 'wrong' in everyday speech.

  • accurate

    Focuses on precision and exactness rather than general truth.

Grammar Patterns

be mistaken about [something]

be mistaken in [doing something]

a mistaken [belief / impression / assumption / identity]

if I'm not mistaken

Usage Note

Frequently used in the fixed phrase 'if I'm not mistaken', which politely introduces a statement the speaker is fairly sure about. The attributive form (a mistaken belief / mistaken identity) is very common in formal and written English.

Common Mistakes

I mistaken the date of the exam.
I was mistaken about the date of the exam.
'mistaken' is an adjective, not a verb; use the verb 'mistake' (past: mistook) for the action of confusing things.
He is mistaken as the thief.
He is mistaken for the thief.
Use 'mistaken for' (confused with someone else), not 'mistaken as'.
She has mistaken about his name.
She was mistaken about his name.
The adjective 'mistaken' partners with 'be' (was mistaken), not 'have'.

Word family

  • mistake
    nounA2
  • mistake
    verbB1
  • mistakenly
    adverbB2
  • unmistakable
    adjectiveB2
  • unmistakably
    adverbC1

Synonym discussion

Sense: adjective/1

All four words describe something that is not true, but they differ in scope and register. 'Wrong' is the broadest and most informal — it covers factual, moral, and practical errors ('wrong answer', 'wrong thing to do'). 'Incorrect' is more neutral and factual, often used in formal contexts like test scores or data ('an incorrect calculation'). 'Inaccurate' focuses on a lack of precision rather than complete error — a measurement can be slightly inaccurate without being entirely wrong. 'Erroneous' is the most formal and appears mainly in writing, describing conclusions, beliefs, or official documents ('erroneous report'). For everyday statements about personal beliefs, 'wrong' and 'mistaken' are the natural choices; for academic or professional feedback, 'incorrect' or 'inaccurate' are more suitable.

wrong ↗incorrect ↗inaccurate ↗erroneous ↗

Common collocations

Nouns

Adverbs

Phrases

  • if I'm not mistaken
  • unless I'm very much mistaken

Prepositions

Etymology

Old NorseMiddle EnglishEnglish

The adjective 'mistaken' developed from the past participle of the Middle English verb 'mistaken', meaning 'to misunderstand'. That verb came from Old Norse 'mistaka' — a combination of 'mis-' (wrongly) and 'taka' (to take). So the original idea was 'to take wrongly', which turned into 'to misunderstand', and later the adjective came to mean 'holding a wrong belief'. The sense of 'wrong in judgement' appeared in the 1500s.