he·li·o·zo·an (hē'lē-ə-zō'ən) n. Any of various aquatic protozoans of the order Heliozoa, having numerous spindlelike pseudopods that radiate from a central cell mass.
[From New Latin Hēliozōa, class name : helio- (from their shape) + -zōa, pl. of -zōon, -zoon.] he'li·o·zo'ic (-zō'ĭk) adj.