Origin: Latin
Meaning: “claw; fingernail”
Gender: Feminine
(AH-niks)
From the name of a gemstone, this name first came into use as a female given name in the 19th-century. Onyx itself derives from the Latin word for “fingernail; claw.”
In the ancient world, the stone was used for cameos, intaglios and vessels. The Onyx was believed to be a remedy against labor pain among Medieval midwives.
Onyx is also used as a synonym for the colour black.
Possible short forms are Oni, Onnie, Nixie or Nyx.
Sources
Legitimate Baby Names 