Trigon /(?)/

Tri·gon

Trigon

n.
  1. A figure having three angles; a triangle.
  2. A division consisting of three signs. (Astrol.)
  3. A kind of triangular lyre or harp. (Gr. & Rom. Antiq.)
  4. The cutting region of the crown of an upper molar, usually the anterior part. That of a lower molar is the Tri"go*nid (). (Zool.)