I don't know what exactly charasters you mean by "bu". There are too many characters for "bu". Each has different meanings.
bu dong mean "I don't understand"
no
Bu means NO
不 but in pinyin it's bu
Bu pretty much means don't. Ex. Wo Bu Xi Huan Mao.
The word "all" in Chinese is 所有(suo-you) or 全部 (quan-bu)
不甜 (bu tian) By putting the word 不 (bu) in front of something, you make it negative.
I believe you mean: 对不起 Duì bù qǐ
The translation for 'no' into Chinese is '不' or 'bu'.
the most likely meaning is "no" but it could also mean 'cloth' or 'step' depending on the context or tone.
cha is the Chinese word for search