Equilateral

a. [Fr. équilatéral, Lat. æquilateralis, fr. æquus, equal, and latus, lateris, side.] Having all the sides equal; as, an equilateral triangle.

Equilateral hyperbola, one whose axes are equal.—Equilateral shell (Conch.), one in which a transverse line drawn through the apex of the umbo bisects the valve, or divides it into symmetrical parts.