Cathedral service
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
mass
'cathedral service' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for mass that I've seen before include "Get together" , "Holy service" , "Lump of material" , "Throng" , "Great deal" .)