SUMPTER Meaning of SUMPTER in English n. archaic 1 a packhorse. 2 any pack-animal (sumpter-mule). [ ME f. OF som(m)etier f. LL f. Gk sagma -atos pack-saddle: cf. SUMMER(2) ] Concise Oxford English dictionary. Краткий оксфордский словарь английского языка. 2012