D defs.my
Entry 1 sense Webster, 1913

Trisection

· Tri·sec·tion · IPA
01 n. The division of a thing into three parts, Specifically: (Geom.) the division of an angle into three equal parts.
  1. 1.
    The division of a thing into three parts, Specifically: (Geom.) the division of an angle into three equal parts.(Geom.)