early 14c., stuffe, "quilted material worn under chain mail," from Old French estoffe "quilted material, furniture, provisions" (Modern French étoffe), from estoffer "to equip or stock," which is of obscure origin; according to French sources it is from Old High German stopfon "to plug, stuff," or from a related Frankish word (see stop (v.)), but OED finds this "open to strong objections."

Etymology Noun Middle English stuff, stuffe "military supplies, provisions, household goods, building material, fabric, filling of a pastry," borrowed from Anglo-French estuffe "provision, stock," noun derivative of estuffer, estoffer "to furnish (with supplies, arms), fill" — more at stuff entry 2 Verb