Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
cū̆prĕus (cȳ̆pr-), a, um, adj. [cuprum], of copper, copper-: bidentes, Pall. Jul. 5: acus, Treb. Claud. 14 (for Plin. 23, 3, 37, § 74, v. Cyprius, s. v. Cyprus).