(n) eukaryotic one-celled living organisms distinct from multicellular plants and animals: protozoa, slime molds, and eukaryotic algae, Syn.division Protista
‖n. pl. [ NL., fr. Gr. prw`tistos first. ] (Zool.) A provisional group in which are placed a number of low microscopic organisms of doubtful nature. Some are probably plants, others animals. [ 1913 Webster ]