Liturgy is utterly fitting (4)
I believe the answer is:
rite
'liturgy' is the definition.
(thesaurus)
'utterly fitting' is the wordplay.
'utterly' shows a homophone (sound like) (as uttered).
'fitting' becomes 'right' (I've seen this before).
'right' is a homophone of 'RITE'.
'is' acts as a link.
(Other definitions for rite that I've seen before include "(Words used in) ceremonial" , "something like mass" , "Uncomplaining person" , "Tries awkwardly to perform rituals" , "Ceremonial act" .)