Part of the Mass (6)
I believe the answer is:
gloria
'part of the mass' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for gloria that I've seen before include "contribution to mass production" , "Portion of Mass" , "Part of the Mass; name" , "-- Gaynor, disco diva" , "Woman's name - Christian hymn praising God" .)