Būm1, n.
n. [Contracted from bottom, which has the same signification.] The buttocks. [Lou.]
2 entries under this word
Bum
Būm2, v. i.
v. i. [D. & Ger. bommen, to resound, Ger. bummen, to hum, O. D. bom, H. Ger. bomme, L. Ger. bunge, drum.] To make a murmuring or humming sound.