Bum /(bŭm)/

Bum

n.
  1. The buttock. [Low]

bum

v. i.

imp. & p. p. bummed; p. pr. & vb. n. bumming

  1. To make murmuring or humming sound.

Phrases & Compounds
to bum around
to wander about idly or aimlessly.

bum

v. t.
  1. To borrow without intention of returning; to cadge; as, to bum a cigarette; to bum a cup of coffee; -- usually with inexpensive items as the object. [informal]

Bum

n.
  1. A humming noise.