Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
russus, a, um, adj., red (very rare): vela, Lucr. 4, 75: gingiva, Cat. 39, 19: tunicae, Val. Imp. ap. Treb. Claud. 14; and Vop. Aur. 13; cf. Gell. 2, 26, 6.