<p><strong>Noun</strong></p><ul><li>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.</li><li>any of several American lizards capable of changing the color of the skin, especially Anolis carolinensis (American chameleon), of the southeastern U.S.</li><li>a changeable, fickle, or inconstant person.</li><li>(initial capital letter) Astronomy: Chamaeleon.</li></ul>