The cry of a big-headed 'pair' (3)
I believe the answer is:
boo
'the cry' is the definition.
(I have seen 'Cry of contempt ' mean 'boo' so perhaps 'cry' could also mean 'boo')
'a big-headed pair' is the wordplay.
'a big-headed' becomes 'b' (this could be a standard abbreviation which I don't know about).
'pair' becomes 'oo' (resembles 00, a pair of ducks in cricket).
'b'+'oo'='BOO'
'of' acts as a link.
Can you help me to learn more?
(Other definitions for boo that I've seen before include "Poor reception" , "get off!" , "Sound made to show disapproval or contempt" , "Shout in disgust" , "Disapproving sound" .)