Onychius
Wordlist from Comphistsem Frankfurt, Jan. 2016:
f NOM sg pos | f VOC sg pos | n ACC sg pos | n VOC sg pos | m VOC sg pos | n NOM sg pos | m NOM sg pos onychius
Lewis & Short, A latin dictionary (1879)
onychius, ŏnychĭus, a, um, adj. onyx, of or belonging to onyx: onychius lapis, i. e. onyx, Tert. adv. Marc. 2, 10.