Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
vaccīnĭum, ii, n., the blueberry, whortleberry: Vaccinium myrtillus, Linn.; Plin. 16, 18, 31, § 77; Verg. E. 2, 18; 2, 50; 10, 39; Ov. Tr. 1, 1, 5; Vitr. 7, 14, 2.
vaccīnus, a, um, adj. [vacca], of or from cows: caro, Plin. 28, 12, 50, § 185: lac, id. 25, 8, 53, § 94: caseus, id. 28, 14, 58, § 204.