On"y*cha (?), n. [NL., from L. onyx, -ychis, onyx, also, a kind of mussel, Gr. , . See Onyx.]
1.
An ingredient of the Mosaic incense, probably the operculum of some kind of strombus.
Ex. xxx. 34.
2.
The precious stone called onyx.
[R.]
© Webster 1913.