Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
1. būris, is, m. (būra, ae, f., Varr. R. R. 1, 19, 2) [acc. to Serv. ad Verg. G. 1, 170 (cf. also Isid. Orig. 20, 14, 2), contr. from βοῦς and οὐρά, ox-tail], the curved hinder part of the plough of the ancients, the plough-beam, Varr. ap. Serv. l. l.
Acc. burim, Verg. G. 1, 170 Serv. and Voss.; Varr. R. R. 1, 19, 2.
2. Būris, is, f., a city of Achaia; acc. Burin, Ov. M. 15, 293.