吧

biā
(onom.) smack!

CEDICT

onomatopoeic

Homographs

吧 bā
  1. bar (loanword) (serving drinks, or providing Internet access etc)
  2. to puff (on a pipe etc)
  3. (onom.) bang
  4. abbr. for 貼吧 tiēbā
吧 ba
  1. (modal particle indicating suggestion or surmise)
  2. ...right?
  3. ...OK?
  4. ...I presume.