Pronunciation: (ku-mē'lē-un, -mēl'yun),[key] —n. 1. 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.
2. any of several American lizards capable of changing the color of the skin, esp. Anolis carolinensis(American chameleon), of the southeastern U.S.
3. a changeable, fickle, or inconstant person.
4. (cap.) Astron.Chamaeleon.