1. Involving three parties
   "trilateral talks"
    
2. Having three sides
   "a trilateral shape was drawn on the board";
   - triangular, three-sided

1. A three-sided polygon
   "A triangle is the simplest form of a trilateral"; "A trigon is the simplest form of a trilateral";
   - triangle, trigon

Derived forms: trilaterals

See also: many-sided, multilateral, mutual, reciprocal

Type of: polygon, polygonal shape

Encyclopedia: Trilateral