Meadow call (3)
I believe the answer is:
baa
'meadow call' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for baa that I've seen before include "not quite consistent set of good A-level results?" , "Statement from those flocking" , "Beastly sound f" , "Cry of a sheep" , "Bleat of a sheep" .)