Английский Этимологический словарь - stem (n.)

- O.E. stemn, stefn "stem of a plant," also "either end-post of a ship" (hence to stem the tide, confused in sense with stem (v.)), from P.Gmc. *stamniz, from base *sta- "stand." Stem-winding watches were advanced and desirable when introduced, hence slang stem-winder "excellent thing" (1892). The phrase stems from, first recorded 1932, translates Ger. stammen aus.