We heard the correct ceremony! (4)
I believe the answer is:
rite
'ceremony' is the definition.
(I know that rite is a type of ceremony)
'we heard the correct' is the wordplay.
'we heard' shows a homophone (sound like).
'the correct' becomes 'right' (right can mean correct).
'right' is a homophone of 'RITE'.
(Other definitions for rite that I've seen before include "Established religious ceremony" , "Tire of ceremony" , "Religious ceremonial sounds correct" , "Custom" , "Ceremony, liturgy" .)