DioeciaDi*[oe]"ci*a\ (d[-i]*[=e]"sh[i^]*[.a]), n. pl. [NL., fr. Gr. di = di`s twice + o'i^kos a house.]1. (Bot.) A Linn[ae]an class of plants having the stamens and pistils on different plants. 2. (Zo["o]l.) A subclass of gastropod mollusks in which the sexes are separate. It includes most of the large marine species, like the conchs, cones, and cowries.