Women collectively behave very heartlessly (4)
I believe the answer is:
bevy
'women' is the definition.
(I have seen 'Many women' mean 'bevy' so perhaps 'women' could also mean 'bevy')
'collectively behave very heartlessly' is the wordplay.
I cannot really understand how this works, but
'very' could be 'v' (abbreviation) and 'v' is present in the answer.
The remaining letters 'bey' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for bevy that I've seen before include "Collective noun for beauties" , "many girls" , "Group of e.g. girls" , "A large group - of beauties?" , "Flock of larks, quails or swans" .)