Meaning

noun engraving or carving in low relief on a stone (as in a brooch or ring)

originBorrowed from Italian cammeo, from Medieval Latin camaeus, of unknown origin. The movie sense is short for “cameo role” referring to a famous person who was playing no character, but him or herself. Like a cameo brooch — a low-relief carving of a person’s head or bust — the actor or celebrity is instantly recognizable. More recently, it has come to refer to any short appearances, whether as a…

Etymology from Wiktionary, CC BY-SA 3.0