sheathe

From Late Middle English shethen (“to put (a sword or knife) into a sheath, sheathe; to provide with a sheath; (figuratively) to have sexual intercourse”) [and other forms], then: probably from Old English scēaþian; or possibly from Middle English sheth, shethe (“holder for a sword, knife, etc., scabbard, sheath”) [and other forms] + -en (suffix forming the infinitive of verbs). Sheth(e) is derived from Old English sċēaþ (“sheath”), from Proto-West Germanic skaiþiju, from Proto-Germanic skaiþiz (“sheath; covering”), from Proto-Indo-European skey- (“to dissect, split”) (possibly from the notion of a split stick with a sword inserted).