but what

phrase

: that … not

—used to indicate possibility or uncertainty

I don't know but what I will go.

Word History

First Known Use

1545, in the meaning defined above

Time Traveler

The first known use of but what was in 1545

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Browse Nearby Words

butut

but what

butyl

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Cite this Entry

Style

“But what.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/but%20what. Accessed 14 Mar. 2026.

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Last Updated: 24 Feb 2026 - Definition revised

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