Sound from a fold (3)
I believe the answer is:
baa
'sound from a fold' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for baa that I've seen before include "Cry of a sheep" , "How one of the fold may sound" , "Lamb's cry" , "Sheep's bleat" , "not quite consistent set of good A-level results?" .)