modal particle, punctuation, verb, noun, pronoun, directional, numeral, measure word, adjective, particle · modal particle indicating a suggestion, command, or request

我们走吧。

modal particle, punctuation, particle, noun, pronoun, adjective, time word, directional, verb, measure word · modal particle indicating a guess, surmise, or presumption, often translated as "...I presume"

他快到了吧。

modal particle · onomatopoeia for a bang or cracking sound

只听吧的一声，木棍折断了。

noun · bar (loanword) (serving drinks, or providing Internet access etc)

这家酒吧的氛围很不错。

verb · to puff (on a pipe etc)

他悠闲地吧着旱烟袋。

modal particle · (onom.) the sound of a smack or crack

吧的一声，打了一个耳光。