E0280500 (ĕk′sŏz-mō′sĭs, -sŏs-)n. The passage of a fluid through a semipermeable membrane toward a solution of lower concentration, especially the passage of water through a cell membrane into the surrounding medium.[ex(o)- + osmosis.]ex′os·mot′ic(-mŏt′ĭk) adj.EncyclopediaSeeexosmosis