Lewis & Short

cĭnĕrĕus, a, um, adj. [cinis], similar to ashes, ash-colored: color, Col. 2, 2, 16; Scrib. 23; Plin. 37, 10, 68, § 183 sq.: terra, id. 35, 16, 54, § 192 uva, id. 14, 3, 4, § 42.
Hence, subst.: cĭnĕrĕum, ĕi, n., a kind of salve, Scrib. Comp. 37; cf.: collyrium spodiacum a quibusdam cinereum dicitur, id. ib. 24 init.