1. An agate, formed by alternate streaks of dark and white chalcedony.

Nuttall's Standard dictionary of the English language By Nuttall, P.Austin

• onlyx,
• tonix,
• onbux,
• oncw,
• onik,
• onyl,
• onix,
• ony,
• oynx,
• onx,
• onlys,
• onys,
• onlz,
• onxy,
• anyq,
• bomyx,
• fornyx,
• konyni,
• inyx,
• knyx

• onus,
• once,
• ONG,
• on-key.

The adjective form of the word "onyx" is "onyxine".

The plural form of the word "onyx" is "onyxes" or "onyces." Both forms are considered acceptable.

The singular form of the word "onyx" remains "onyx".