Sheepish utterance of a bachelor with heavy heart (3)
I believe the answer is:
baa
'sheepish utterance' is the definition.
(I've seen this in another clue)
'bachelor with heavy heart' is the wordplay.
'bachelor' becomes 'BA' (Bachelor of Arts).
'with' is a charade indicator (letters next to each other).
'heart' indicates the central letters.
The middle letter of 'heavy' is 'a'.
'ba'+'a'='BAA'
'of a' acts as a link.
(Other definitions for baa that I've seen before include "Sound of a lamb" , "Sound from a ewe" , "How one of the fold may sound" , "Cry of a sheep" , "Sound of sheep" .)