n. and order of plankton, in some classifications it is considered a phylum of the kingdom Protista; in others it is included in the plant phylum Pyrrophyta. Its members usually have two flagella, one of which extends from its center.
Syn. -- order Dinoflagellata, Cilioflagellata, order Cilioflagellata. [ WordNet 1.5 +PJC ]

‖n. pl. [ NL., fr.L. flagellatus, p. p. See Flagellate, v. t. ] (Zool.) An order of Infusoria, having one or two long, whiplike cilia, at the anterior end. It includes monads. See Infusoria, and Monad. [ 1913 Webster ]

‖n. pl. [ NL. See Radiate, and Flagellata. ] (Zool.) A group of Protozoa having both flagella and pseudopodia. [ 1913 Webster ]