Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
ĕbŏrĕus, a, am, adj. [ebur], made of ivory, ivory: Juppiter, Plin. 36, 5, 4, § 40: mensae, Dig. 33, 7, 12, § 43: oppida, Quint. 6, 3, 61 Spald.