1 of 2


: having an equilateral triangular cross section
used especially of a file


2 of 2


or less commonly three-square rush [so called from the triangular stems] : any of various rushes of the genus Scirpus
especially : chairmaker's rush
: a three-square file

Word History



Middle English thre sqware having three equal sides, from three, thre three + sqware, square square

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Dictionary Entries Near three-square

Cite this Entry

“Three-square.” Dictionary, Merriam-Webster, Accessed 21 Jun. 2024.

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