Bad language from goatherd (4)
I believe the answer is:
oath
'bad language' is the definition.
(I've seen this before)
'from goatherd' is the wordplay.
'from' says the answer is hidden in the clue.
'OATH' is hidden within 'goatherd'.
(Other definitions for oath that I've seen before include "A curse or a vow" , "blasphemy" , "One sworn" , "Curse or solemn promise" , "swearing" .)