How do you pronounce bad in Gaelic?

Answer 1

Bh at the beginning of a word is 'w' in Galway and Donegal if followed by a/o/u

and 'v' if followed by e/i. In Cork and Kerry it is 'v' in both cases and this is the case in Scottish Gaelic as well.

Medially and finally is more problematic as it varies by dialect even within Irish and Scottish Gaelic. Wikipedia has an article on Scottish Gaelic phonology and Irish phonology that can explain in more detail.

Answer 2

The question is unclear: the English word "bad" is "dona"in Gaelic;

the Gaelic word "bad" means "place/part/area".