[bung] n [ME, fr. MD bonne, bonghe] (15c) 1: the stopper esp. in the bunghole of a cask; also: bunghole
2: the cecum or anus esp. of a slaughtered animal
[2]bung vt (1589) 1: to plug with or as if with a bung
2. Brit: throw, toss "~ a spanner into the works --P. G. Wodehouse"