The word has a couple of meanings depending on the context in which it is used.

1. It can be used to refer to a fart.

‘Daai man o shapile bomb.’

2. It can also be used to refer to ignoring someone.

I sent this one a text in the morning yaz,ong shapile ka bomb kere le nou😂 obvs watseba ke batla chelete 😂😂😂

— pumpkin. (@minnie_luu) November 23, 2017