n. [ NL., fr. Gr. &unr_;. ] (Gr. Antiq.) The place at Athens where the meetings of the people were held for making decrees, etc. [ 1913 Webster ]
n. [ L., fr. Gr. &unr_; a claw, finger nail, a veined gem. See Nail, and cf. Onycha. ]
Onyx marble,
Mexican onyx
a. Deep, jet-black. [ PJC ]