Patronised and offended in South Atlantic (9)
I believe the answer is:
sponsored
'patronised' is the definition.
('sponsor' can be a synonym of 'patronize')
'offended in south atlantic' is the wordplay.
'offended' becomes 'sore'.
'in' is an insertion indicator.
'south' becomes 's' (synonyms).
'atlantic' becomes 'pond' (as in 'across the pond').
's'+'pond'='spond'
'sore' going within 'spond' is 'SPONSORED'.
'and' is the link.
(Other definitions for sponsored that I've seen before include "(Of event) supported financially" , "With backing" .)