Lewis & Short

ăpŏprŏēgmĕnon, i, n., = ἀποπροηγμένον; in the philos, lang. of the Stoics, that which is to be rejected (opp. proegmenon): puto concedi nobis oportere, ut Graeco verbo utamur, si quando minus occurret Latinum, ne hoc ephippiis et acratophoris potius quam proëgmenis et apoproëgmenis concedatur, Cic. Fin. 3, 4, 15.