Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
prīmas, ātis, comm. [primus], one of the first or principal, chief, excellent, noble (postclass.): apud primatem feminam, App. M. 2, p. 123, 1: primatis civitatis filius, id. ib. 2, p. 124, 35 (Oud. principum): notitia primatium urbium, Cod. Th. 7, 18, 13: periculo primatum officii, ib. 1, 12, 3; Vulg. 2 Macc. 4, 21.