First celebrant holds back return (5)
I believe the answer is:
elect
'return' is the definition.
(I've seen this before)
'first celebrant holds back' is the wordplay.
'holds' indicates the answer is hidden within the clue.
'back' says the letters should be written in reverse.
'tcele' is hidden within 'first celebrant'.
'tcele' reversed gives 'ELECT'.
(Other definitions for elect that I've seen before include "Opt for; chosen" , "Appoint through ballot" , "Exclusive group" , "Put in power by voting" , "Choose; chosen" .)