n. [ L. iasponyx, Gr. &unr_;. See Jasper, and Onyx. ] (min.) An onyx, part or all of whose layers consist of jasper. [ 1913 Webster ]

‖n. [ Gr. ke`ras, -atos, horn + &unr_; puncture. ] (Med.) The operation of removing a cataract by thrusting a needle through the cornea of the eye, and breaking up the opaque mass. [ 1913 Webster ]

‖n. [ NL., from Gr. me`gas, mega`lh, great + 'o`nyx claw. ] (Paleon.) An extinct quaternary mammal, of great size, allied to the sloth. [ 1913 Webster ]

n. [ L., fr. Gr. &unr_; a claw, finger nail, a veined gem. See Nail, and cf. Onycha. ] 1. (Min.) Chalcedony in parallel layers of different shades of color. It is used for making cameos, the figure being cut in one layer with the next as a ground. [ 1913 Webster ]

2. Same as Mexican onyx. [ PJC ]

3. A deep jet-black color. [ PJC ]

Onyx marble,
Mexican onyx, a banded variety of marble or calcium carbonate resembling onyx. It is obtained from Mexico in various colors ranging from white to deep black. [ 1913 Webster +PJC ]

a. Deep, jet-black. [ PJC ]

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_;. See Sard, and Onyx. ] (Min.) A variety of onyx consisting of sard and white chalcedony in alternate layers. [ 1913 Webster ]

‖n. [ NL., fr. Gr. &unr_; (see Tri-) + &unr_; a claw. ] (Zool.) A genus of fresh-water or river turtles which have the shell imperfectly developed and covered with a soft leathery skin. They are noted for their agility and rapacity. Called also soft tortoise, soft-shell tortoise, and mud turtle. [ 1913 Webster ]

☞ The common American species (Trionyx ferox syn. Aspidonectus ferox) becomes over a foot in length and is very voracious. Similar species are found in Asia and Africa. [ 1913 Webster ]