Proteus

·noun A changeable protozoan; an Amoeba.

II. Proteus ·noun A sea god in the service of Neptune who assumed different shapes at will. Hence, one who easily changes his appearance or principles.

III. Proteus ·noun A genus of aquatic eel-shaped amphibians found in caves in Austria. They have permanent external gills as well as lungs. The eyes are small and the legs are weak.