Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
prīmātus, ūs, m. [primas], the first place or rank, preference, pre-eminence, primacy (ante-class. and in post-Aug. prose): alii dant primatum bonis pratis, Varr. R. R. 1, 7, 10: primatum obtinere apud regem, Plin. 24, 17, 102, § 165: donare aliquem primatu, id. 8, 5, 5, § 12; 13, 12, 24, § 79 (opp. secundatus).