Proper ceremony, so we hear (5)
I believe the answer is:
right
'proper' is the definition.
(associated in meaning)
'ceremony so we hear' is the wordplay.
'ceremony' becomes 'rite' (rite is a kind of ceremony).
'so we hear' shows a homophone (sound like).
'rite' is a homophone of 'RIGHT'.
(Other definitions for right that I've seen before include "Privy Councillors are so honourable" , "Morally correct" , "Just - correct - title" , "blue, politically" , "True - just claim" .)