Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
successor, ōris, m. [succedo, II.], a follower, successor in office, possession, time, etc. (class.; cf. vicarius): conjunctissimus, Cic. Fam. 3, 3, 1; cf.: successori decessor invidit, id. Scaur. Fragm. 33; id. Prov. Cons. 15, 37; id. Fl. 14, 33; id. Fam. 3, 6, 2: successorem alicui mittere, to remove from office, Liv. 23, 27, 12; cf. id. 32, 28, 1: legato eum consulari successorem dedisse, Suet. Aug. 88; id. Dom. 1: successorem accipere, to be removed, Plin. Ep. 8, 13, 23: successores Alexandri, Quint. 12, 10, 6: studii successor et heres, Ov. M. 3, 589: quo successore (Philoctete) sagittae Herculis utuntur, i. e. the succeeding possessor, inheritor, id. ib. 13, 51: alieni criminis successor, Dig. 48, 19, 26: successore novo vincitur omnis amor, by a new favorite, Ov. R. Am. 462; cf.: novus habendus (clipeo), id. M. 13, 119: propositi successor honoris Junius, id. F. 5, 77: successor fuit hic tibi, Galle; Propertius illi, i. e. he followed you, wrote after you, id. Tr. 4, 10, 53.
Of a female: Phoebe, Fraternis successor equis, Corn. Sev. ap. Charis. p. 66 P.
successōrĭus, a, um, adj. [successor], of or belonging to succession, successory (post-class.; esp. freq. in jurid. Lat.): de successorio edicto, Dig. 38, 9, 1 pr.: ex successorio capite, ib. 22, 6, 1, § 3: successorio jure aliquid tenere, Amm. 14, 8, 5.