Supports trendy contest (12)
I believe the answer is:
championship
'contest' is the definition.
(thesaurus)
'supports trendy' is the wordplay.
'supports' becomes 'champions' (champion can mean to support or recommend).
'trendy' becomes 'hip' (I've seen this in another clue).
'champions'+'hip'='CHAMPIONSHIP'
(Other definitions for championship that I've seen before include "Contest - advocacy" , "Sporting contest to decide overall winner" , "title" .)