Lewis & Short

lentor, ōris, m. [lentus], pliancy, flexibility; toughness, stickiness, viscosity (Plinian; cf. lentitia): ad rotarum axes lentore fraxinus utilis, Plin. 16, 43, 84, § 229: lentor resinosus, id. 13, 6, 12, § 54: picis, id. 16, 11, 22, § 53: usque ad lentorem aliquid subigere, id. 17, 14, 24, § 111.