Agent sent out regrets (7)
I believe the answer is:
repents
'regrets' is the definition.
('repent' can be a synonym of 'regret')
'agent sent out' is the wordplay.
'agent' becomes 'rep' (short for representative).
'out' is an anagram indicator (out can mean wrong or inaccurate).
'sent' anagrammed gives 'ents'.
'rep'+'ents'='REPENTS'
(Other definitions for repents that I've seen before include "Expresses sorrow for sin" , "Turns away from evil" , "Feels remorse for, sin perhaps" , "Present (anag.)" , "Feels sincere remorse" .)