noun

bum

The part of the body you sit on.

The toddler lands on his bum and starts to laugh.

Etymology

Origin uncertain. The buttocks word has a Middle English history distinct from the later American word for an idle person.

More examples

  • These jeans are too tight around my bum.
  • My bum hurts after the long bike ride.
  • She brushes sand off her bum.

Forms

bum · bums

Similar words

butt
A more common informal American term for the same body part.
buttocks
A neutral anatomical term for the two rounded fleshy parts.
rear
A milder term that can also mean the back.