Partial farewell for a sheep (3)
I believe the answer is:
ewe
'a sheep' is the definition.
(a ewe is a female sheep)
'partial farewell for' is the wordplay.
'partial' says the answer is hidden in the clue.
'EWE' is hidden in the letters of 'farewell for'.
(Other definitions for ewe that I've seen before include "Partner to ram" , "Ram's partner?" , "Lamb's mother" , "Female in a fleece?" , "Scottish loch" .)