Milk source for Roquefort cheese (3)
I believe the answer is:
ewe
'milk source for roquefort cheese' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ewe that I've seen before include "One needing pastoral care" , "Wool producer" , "Lamb's dam" , "Language" , "The sort of beast" .)