Any of various eukaryotic organisms belonging to the kingdom Protoctista in some classification systems. Protoctists include unicellular and multicellular organisms that are not fungi, plants, or animals. They are usually now referred to as protists.
Origin of protoctistFrom New Latin Prōtoctista kingdom name Greek prōto- proto- Greek ktistos produced, created ( from ktizein to create, establish ; see tkei- in Indo-European roots.)
- Of or pertaining to these organisms