Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
vester (vost-), tra, trum, pron. poss. [vos], your: voster senex, Plaut. Most. 3, 2, 60 (dub.; al. noster): animi vostri, id. Am. prol. 58: num sermonem vestrum aliquem diremit noster interventus? Cic. Rep. 1, 11, 17: vestra quae dicitur vita mors est, id. ib. 6, 14, 14: vestrum est dare, vincere nostrum, Ov. F. 4, 889: patres, Cic. Imp. Pomp. 5, 11.
For obj. gen. of vos: nec esse in vos odio vestro consultum ab Romanis credatis, from hatred towards you, Liv. 30, 44, 7.
Subst.: ibi voster cenat, your master, Plaut. Stich. 5, 2, 15: quid ego vos de vestro impendatis hortor? Liv. 6, 15, 10: vostrorum, vostrarum, full form of gen. plur., from which vostrum (vestrum), used as gen. of vos, is contracted; the full form is found subst. (ante-class.): pars vostrorum intellegit, Plaut. Most. 1, 3, 123: neutram vostrarum, id. Stich. 1, 2, 84; id. Ps. 1, 2, 53; id. Aul. 2, 4, 42.