A substance that gives greases their consistency and holds oil. Thickeners used include: metal soaps for calcium soap grease, lithium soap grease, sodium soap grease, complex greases for aluminum complex greases, barium complex base, sodium complex grease, synthetic, organic or inorganic thickeners for polyurea based greases, gel greases (bentonite, micro-dispersed silicic acids) The grease displays particular characteristics depending on the thickener.