An Etymological Dictionary of Astronomy and Astrophysics

The process by which solvent molecules pass through a partially permeable
membrane from a dilute solution into a more concentrated solution, thus equalizing the concentrations of materials on either side of the membrane. → permeability.

Etymology (EN): Extracted from Fr. endosmose “endosmosis” and exosmose “exosmosis,” from Gk. prefixed osmos “a thrusting, a pushing,” from othein “to push, to thrust;” cf. Av. vādāiiôit “breaks through, hunts,” vadah- “wedge;” Mod.Pers. guvah, gavah “wedge;” Skt. vadh- “to slay, kill,” vadha- “killer.”

Etymology (PE): Tarârân, literally “pushing across,” from tarâ-, → trans-, + rân present stem of rândan “to push, drive, cause to go,”
causative of raftan “to go, walk, proceed” (present tense stem row-, Mid.Pers. raftan, raw-, Proto-Iranian *rab/f- “to go; to attack”).