Religious ceremony contributing to spirituality (6)
I believe the answer is:
ritual
'religious ceremony' is the definition.
(thesaurus)
'contributing to spirituality' is the wordplay.
'contributing to' indicates a hidden word.
'RITUAL' can be found hidden inside 'spirituality'.
(Other definitions for ritual that I've seen before include "Ceremony following a prescribed order" , "Customary (eg religious) practice" , "Ceremony or protocol" , "Ceremony, solemn procedure" , "Ceremony, regular procedure" .)