The term 'aluminum foil alternative' refers to two materials that can be used instead of aluminum foil: Saran (5 letters) and waxpaper (8 letters). Saran is a brand of plastic wrap made from polyvinylidene chloride, which is a type of plastic that is resistant to moisture and grease. Waxpaper is a thin paper coated with a layer of wax, which makes it water-resistant and non-stick. Both materials are commonly used in the kitchen for food storage and preparation.