Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
quinquĕrēmis, is, adj. [quinque-remus]: decem quinqueremes naves, having five banks of oars, Liv. 41, 9, 1.
As subst.: quinquĕrēmis, is, f., a ship or galley having five banks of oars, a quinquereme (class.): in quinqueremi, Cic. Verr. 2, 4, 46, § 103: una, Liv. 42, 48; 37, 12; Plin. 7, 56, 57, § 208.