[proh-tuh-zoh-uh
n] 
noun, plural -zo⋅ans, (especially collectively) -zo⋅a [-zoh-uh] , adjective Biology| 1. | any of a diverse group of eukaryotes, of the kingdom Protista, that are primarily unicellular, existing singly or aggregating into colonies, are usually nonphotosynthetic, and are often classified further into phyla according to their capacity for and means of motility, as by pseudopods, flagella, or cilia. |
| 2. | of, pertaining to, or characteristic of a protozoan. |
| pro·to·zo·an (prō'tə-zō'ən) n. pl. pro·to·zo·ans or pro·to·zo·a (-zō'ə) also pro·to·zo·ons Any of a large group of single-celled, usually microscopic, eukaryotic organisms, such as amoebas, ciliates, flagellates, and sporozoans. [From New Latin Protozōa, former subkingdom name : proto- + -zōa, pl. of -zōon, -zoon.] pro'to·zo'an, pro'to·zo'al, pro'to·zo'ic adj. |
protozoan pro·to·zo·an (prō'tə-zō'ən) or pro·to·zo·on (-ŏn')
n. pl. pro·to·zo·a (-zō'ə) or pro·to·zo·ans or pro·to·zo·a or pro·to·zo·ons
Any of a group of single-celled, usually microscopic, eukaryotic organisms, such as amoebas, ciliates, flagellates, and sporozoans.