D defs.my
Entry 3 senses Webster, 1913

Semicircle

· Sem·i·cir·cle · IPA
01 n. The half of a circle; the part of a circle bounded by its diameter and half of its circumference.
  1. 1.
    The half of a circle; the part of a circle bounded by its diameter and half of its circumference.
  2. 2.
    A body in the form of half of a circle, or half of a circumference.
  3. 3.
    An instrument for measuring angles.