The Collaborative International Dictionary
Trigeminous
Trigeminous \Tri*gem"i*nous\, a. [L. trigeminus born three
together; tri- (see Tri-) + geminus twin. Cf.
Tergeminous.]
Born three together; being one of three born at the same
birth; also, threefold.
--E. Phillip?.
Wiktionary
trigeminous
a. 1 born three together; being one of three born at the same birth 2 threefold