An Etymological Dictionary of Astronomy and Astrophysics

Geology: The act or state of eroding; state of being eroded.
A general term applied to the wearing away and movement of earth materials by the action of water, glaciers, winds, gravity, etc.

Etymology (EN): From M.Fr. erosion, from L. erosionem (nom. erosio), from erodere “to gnaw away,” from → ex- “away” + rodere “to gnaw, eat away” (cf. Fr. and E. animal rat).

Etymology (PE): Farsâyeš, from far- intensive prefix “much, abundant” (Mid.Pers. fra- “forward, before; much; around;”
O.Pers. fra- “forward, forth;” Av. frā, fərā-, fra- “forward, forth; excessive;” cf. Skt. prá- “before; forward, in fron;” Gk. pro “before, in front of;” L. pro “on behalf of, in place of, before, for;” PIE *pro-)

• verbal noun of sâyidan, variants sâbidan “to bruise, file,” pasâvidan “to touch;” Khotanese sauy- “to rub;” Sogdian ps’w- “to touch;” Proto-Iranian *sau- “to rub.”