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Any of numerous eukaryotic organisms that are not fungi, plants, or animals and are chiefly unicellular or colonial. Protists that are multicellular do not have cells differentiated into tissues. The protists include the protozoans, certain algae, oomycetes, and slime molds.
[From New Latin Prōtista, former kingdom name, from Greek prōtista, neuter pl. of prōtistos, the very first, superlative of prōtos, first; see per in Indo-European roots.]
pro·tis′tan (-tĭs′tən) adj. & n.
pro′tis·tol′o·gy (prō′tĭ-stŏl′ə-jē) n.
(Biology) biology the branch of biology that concentrates on protists