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bird's mouth

American  

noun

Carpentry.

  1. a right-angled notch cut in the underside of a rafter for fitting over a longitudinal member, as a wall plate.

Etymology

Origin of bird's mouth

First recorded in 1815–25

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.