D defs.my
Entry 1 sense Webster, 1913

Bird's-mouth

· IPA
01 n. An interior angle or notch cut across a piece of timber, for the reception of the edge of another, as that in a rafter to be laid on a plat…
  1. 1.
    An interior angle or notch cut across a piece of timber, for the reception of the edge of another, as that in a rafter to be laid on a plate; -- commonly called crow's-foot in the United States.(Arch.) Also: crow's-foot