Sort of hymn - carol is seen to be different (11)
I believe the answer is:
recessional
'sort of hymn' is the definition.
'carol is seen to be different' is the wordplay.
'to be different' indicates anagramming the letters (I've seen 'is different' mean this).
'carol'+'is'+'seen'='carolisseen'
'carolisseen' is an anagram of 'RECESSIONAL'.
(Other definitions for recessional that I've seen before include "'Lest we forget' poem (Kipling)" , "song after service" , "Hymn sung on withdrawal" , "to hard times?" , "Hymn sung at end of service" .)