[ 'trʌɪgɒn ]
■ noun
1》 an ancient triangular lyre or harp.
2》 a triangular cutting region formed by three cusps on an upper molar tooth.
3》 archaic a triangle.
Origin
C17 (earlier (C16) as ~al ): via L. from Gk trigōnon , neut. of trigōnos 'three-cornered'.