semisonans

A New Latin Dictionary by Charlton T. Lewis Ph.D. and Charles Short, LL. D.

sēmĭ-sŏnans, antis, adj. [sono],

halfsounding , semi-vocal : littera, i. e. a semivowel , App. de Mundo, 16, 29; Ter. Carm. Her. p. 2406 P.; Isid. 1, 4, 4.