semicircle Meaning, Definition & Usage

  1. noun a plane figure with the shape of half a circle
    hemicycle.

WordNet

Sem"i*cir`cle noun
Definitions
  1. (a) The half of a circle; the part of a circle bounded by its diameter and half of its circumference. (b) A semicircumference.
  2. A body in the form of half of a circle, or half of a circumference.
  3. An instrument for measuring angles.

Webster 1913