Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
1. ēr, ēris, m. [χήρ], a hedgehog, Nemes. Cyneg. 57.
2. Er (Her), Eris, m., a Pamphylian, who, according to legend (cited in Plato Polit. 10, 12, p. 626), rose from the dead, Cic. Rep. 6, 3; 6 sq.