Trigon

n.
  1. A figure having three angles; a triangle.
  2. (Astrol.) The cutting region of the crown of an upper molar, usually the anterior part. That of a lower molar is the Tri"go*nid ().
    1. A division consisting of three signs.
    2. Trine, an aspect of two planets distant 120 degrees from each other.
    3. A kind of triangular lyre or harp.
    4. A kind of game at ball played by three persons standing at the angular points of a triangle.