Prō'te-ŭs or Prō'teĭs, n.

n. [Lat., fr. Gr. Πρωτεύς.] 1. (Myth.) A marine deity, the son of Oceanus and Tethys, whose distinguishing characteristic was the faculty of assuming different shapes; hence, one who easily changes his appearance or principles. 2. (Zoöl.) (a.) A genus of batrachian reptiles, allied to the siren, salamanders, and frogs. (b.) A genus of homogeneous infusoria, the forms of which are incessantly changing.