|eks+ noun
Etymology: alteration (influenced by Greek -sis ) of earlier exosmose, from French, from ex- ex- (I) + Greek ōsmos action of thrusting or pushing — more at endosmosis
1. : osmotic diffusion toward the outside of a cell or vessel
2. : passage of material through a membrane from a region of higher to a region of lower concentration — used chiefly in biology; compare endosmosis 1