Lewis & Short

Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.

Sĭmōnĭdes, is, m., = Σιμωνίδης, a celebrated lyric poet of Cos, Cic. Rep. 2, 10, 20; id. Tusc. 1, 42, 101; 1, 24, 59; id. N. D. 1, 22, 60; id. Div. 1, 27, 56; Quint. 10, 1, 64; 11, 2, 11 al.
Hence, Sĭmōnĭdēus, a, um, adj., of or belonging to simonides: lacrimae, i. e. poems of Simonides that moved the reader to tears, Cat. 38, 8 (cf. Hor. C. 2, 1, 38; Quint. 10, 1, 64).