monocyttarian,a.andn.Zool.|mɒnəʊsɪˈtɛərɪən| [f.mod.L. Monocyttaria neut. pl. (f.Gr. µόνο-ς mono- + κύτταρ-ος cell) + -an.] a.adj. Belonging to the group Monocyttaria of Radiolarians, which have a single central capsule; unicapsular. b.n. A member of this group. 1890in Century Dict.