all in one's mind

phrase

: existing only in one's imagination

He thinks he's very sick, but it's all in his mind.

Word History

First Known Use

1931, in the meaning defined above

Time Traveler

The first known use of all in one's mind was in 1931

See more words from the same year

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Style

“All in one's mind.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/all%20in%20one%27s%20mind. Accessed 24 Mar. 2026.

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Last Updated: 24 Feb 2026 - Definition revised

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all in one's mind

phrase

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