take someone at their word

take someone at their word (third-person singular simple present takes someone at their word, present participle taking someone at their word, simple past took someone at their word, past participle taken someone at their word)

1. (transitive) To take someone literally even though they may not have been serious; to take someone seriously even though they were joking; to take up a challenge that was initially meant as a joke.
2. (transitive) To take someone's word for it, to believe someone without having the means to check that what they said is true.
   • 2023, Phil Illy, “Autosexuality Beyond Gender”, in Autoheterosexual: Attracted to Being the Other Sex‎^[1], Houndstooth Press, →ISBN, →OCLC, page 447:

     There’s no way to objectively know if a particular alterhuman individual is actually an otherkin, otherkith, or otherlink. As with matters of gender identity, they have to be taken at their word—sometimes quite literally: it might be a word you've never heard before.

• on the face of it
• take at face value

• “take someone at their word” (US) / “take someone at their word” (UK) in Macmillan English Dictionary.
• “take someone at their word”, in Lexico, Dictionary.com; Oxford University Press, 2019–2022.
• “take sb at their word”, in Collins English Dictionary.
• “take someone at his word”, in Collins English Dictionary.