- any of numerous Old World lizards of the family Chamaeleontidae, characterized by the ability to change the color of their skin, very slow locomotion, and a projectile tongue.
- any of several American lizards capable of changing the color of the skin, especially Anolis carolinensis (American chameleon), of the southeastern U.S.
- a changeable, fickle, or inconstant person.
- (initial capital letter) Astronomy. Chamaeleon.
- any lizard of the family Chamaeleontidae of Africa and Madagascar, having long slender legs, a prehensile tail and tongue, and the ability to change colour
- a changeable or fickle person
mid-14c., camelion, from Old French caméléon, from Latin chamaeleon, from Greek khamaileon “the chameleon,” from khamai “on the ground” (also “dwarf”), akin to chthon “earth” (see chthonic) + leon “lion” (see lion). Perhaps the large head-crest on some species was thought to resemble a lion’s mane. The classical -h- was restored in English early 18c. Figurative sense of “variable person” is 1580s. It formerly was supposed to live on air (cf. “Hamlet” III.ii.98).