osmosis n.

"the tendency of fluids to pass through porous partitions and mix with each other; the diffusion of fluids through membranes," 1867, Latinized from osmose (1854), a shortened form of endosmose "inward passage of a fluid through a porous septum" (1829), from French endo- "inward" + Greek ōsmos "a thrusting, a pushing," from stem of ōthein "to push, to thrust," from PIE *wedhe- "to push, strike" (source also of Sanskrit vadhati "pushes, strikes, destroys," Avestan vadaya- "to repulse"). Figurative sense is from 1900. Related: Osmotic (1854, from earlier endosmotic); osmotically.