An Etymological Dictionary of the German Language/löschen
löschen (1.), vb., ‘to extinguish, go out’; in the ModHG. vb. two MidHG. vbs. are comprised, MidHG. lëschen (most frequently erlëschen), str. vb., ‘to cease to burn, go out,’ and the corresponding factitive lęschen, ‘to extinguish’; comp. OHG. lëskan, irlëskan, intrans., and lęsken, trans.; this verbal stem is unknown to the other Teut. languages. The sk of OHG. lëskan is really a suffix of the pres. stem (see dreschen and waschen), as may be inferred from the connection with the Teut. root leg (see liegen); erlöschen is lit. ‘to lie down.’
löschen (2.), vb., ‘to discharge a ship,’ borrowed from the equiv. LG., Du. lossen; comp. Dan. losse, Swed. lossa; the origin and early history of the cognates are unknown (comp. Boot, Bord, and Rahe).