Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
Mŏnaeses, is, m., a king of the Parthians: Monaeses et Pacori manus, Hor. C. 3, 6, 9 (Monaeses et Pacorus reges Persarum fuere, Schol. Acr.).