neˈreidous,a.Zool. [f. as prec. + -ous.] Resembling a nereid; belonging to the Nereidæ. 1839Darwin Voy.Nat. xiii. 305 Crawling nereidous animals of a multitude of forms.1845Ibid. (ed. 2) xx. 465 Nereidous worms, which perforate every block of dead coral.