pro·toc·tist (prə-tōk'tĭst) n. Any of various unicellular eukaryotic organisms and their multicellular, coenocytic, or colonial descendants that belong to the kingdom Protoctista according to some taxonomic systems. The protoctists include the protozoans, slime molds, various algae, and other groups. In many new classification systems, all protoctists are considered to be protists.
[From New Latin Prōtoctista, kingdom name : Greek prōto-, proto- + Greek ktistos, produced, created (from ktizein, to create, establish; see tkei- in Indo-European roots).]
protoctist pro·toc·tist (prō'tək-tĭst) n. A eukaroytic, unicellular organism belonging to the kingdom Protoctista, which includes protozoa, slime molds, and certain algae.