Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
sapsa, pron. [contr. from sa-, i. e. suaipsa; cf.: sam, sas; v. suus init.], his (her, its) own (ante-class. only in the two foll. passages): quo res sapsa loco sese ostentatque jubetque, Enn. ap. Fest. s. v. sas, p. 325 Müll.; so, sapsa res, Pac. ap. ib. p. 325 ib. (Trag. Rel. p. 99 Rib.).