Tom telephones expressing disapproval (8)
I believe the answer is:
catcalls
'expressing disapproval' is the definition.
I can't judge whether this defines the answer.
'tom telephones' is the wordplay.
'tom' becomes 'cat' (a tom is a male cat).
'telephones' becomes 'calls' ('call' can be a synonym of 'telephone').
'cat'+'calls'='CATCALLS'
Can you help me to learn more?
(Other definitions for catcalls that I've seen before include "Shrill disapproving whistles of feline origin" , "Shrill whistles of disapproval - feline?" , "Derisive shouts" .)