gaine

sheath, scabbard (for dagger etc.); casing, sheathing, sheath (of a cable); sheath

Inherited from Middle French guaine, from Old French guaïne, inherited from Latin vāgīna (“sheath, scabbard”). Doublet of borrowed vagin. Cognate with Italian guaina, Catalan beina, Spanish vaina, Portuguese bainha. The change of the onset from Vulgar Latin /v/ to Old French /(ɡ)w/ is due to Germanic influence. One theory sees in it a confluence with Frankish *wāgi (“cup”, compare Old English wǣġe). Alternatively it might be simply that as a military term the word was used most frequently among