Webster's Revised Unabridged Dictionary · 1913

Diocia

Diocia (di*ē"shi*ȧ) , noun, plural

[New Latin, from Greek di = di`s twice + o'i^kos a house.]

1.
(Botany) A Linnaan class of plants having the stamens and pistils on different plants.
2.
(Zoology) 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.

Also: Dioecia