evaginate

Evaginate, ē-vaj′i-nāt, v.t. to draw from a sheath.—n.

The original anterior vesicle from which the hemispheres evaginate is composed, as already shown, of an anterior part or telencephalon and a posterior or thalamencephalon; the whole forming the third ventricle in the adult.

Evaginate: extruded by eversion; turned inside out when extruded.