Lewis Short
(adjective) : optīvus, a, um, opto
* Chosen (poet. and in post-class. prose): cognomen,Hor. Ep. 2, 2, 101: optivi vocantur hi (tutores) qui ex optione sumuntur,Gai. Inst. 1, 154 (opp. to dativi).
Charlton T. Lewis, Charles Short, A Latin Dictionary