Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
anguīnus, a, um, adj. [anguis], of or pertaining to the serpent, snaky: cervix, Pac. ap. Cic. Div. 2, 64: capillus Eumenidum, Cat. 64, 193: pellis, Cato, R. R. 73: cucumis, Varr. R. R. 1, 2, 25: adeps, Plin. 30, 5, 12, § 37: vernatio, id. 30, 3, 8, § 24: cor, id. 30, 3, 8, § 23 al.
Hence, anguīnum, i, n. (sc. ovum), a snake’s egg, Plin. 29, 3, 12, § 52.