Turned on friend accepting popular commission (8)
I believe the answer is:
nominate
'commission' is the definition.
(thesaurus)
'turned on friend accepting popular' is the wordplay.
'turned' says the letters should be written backwards.
'friend' becomes 'mate' (mate is a kind of friend).
'accepting' indicates putting letters inside (inserted letters are accepted).
'popular' becomes 'in' ('in' can mean trendy).
'on' written backwards gives 'no'.
'mate' going around 'in' is 'minate'.
'no'+'minate'='NOMINATE'
(Other definitions for nominate that I've seen before include "Propose - name" , "give name" , "Put forward (as candidate for election)" , "Propose for office" , "Pick as a candidate" .)