Mounted second-rate attack giving abuse (7)
I believe the answer is:
upbraid
'abuse' is the definition.
(thesaurus)
'mounted second-rate attack' is the wordplay.
'mounted' becomes 'up' (I've seen this in other clues).
'second rate' becomes 'b'.
'attack' becomes 'raid' (raiding is a kind of attacking).
'up'+'b'+'raid'='UPBRAID'
'giving' is the link.
(Other definitions for upbraid that I've seen before include "Criticise or scold" , "Chastise" , "Beam used for detection of aircraft" , "Scold over arid pub" , "Rebuke, scold severely" .)