marsileaceous,a.Bot.|mɑːsɪlɪˈeɪʃəs| [f.mod.L. Marsileāce-æ (f.Marsilea: see prec.): see -aceous.] Belonging to the family Marsileaceæ. 1856in Mayne Expos.Lex.1862Ansted Channel Isl. ii. viii. (ed. 2) 184 A little marsiliaceous plant (Isoetes hystrix).