Reprimand son, unfriendly in general, at first (8)
I believe the answer is:
scolding
'reprimand' is the definition.
(scolding is a kind of reprimand)
'son unfriendly in general at first' is the wordplay.
'son' becomes 's'.
'unfriendly' becomes 'cold' ('cold' can be similar in meaning to 'unfriendly'**).
'at first' suggests taking the first letters.
The first letter of 'general' is 'g'.
's'+'cold'+'in'+'g'='SCOLDING'
(Other definitions for scolding that I've seen before include "lecture" , "telling-off" , "Rebuking, berating" .)