Rate endless church sermon (6)
I believe the answer is:
speech
'sermon' is the definition.
(thesaurus)
'rate endless church' is the wordplay.
'rate' becomes 'speed' (rate at which something is moving).
'endless' means to remove the last letter.
'church' becomes 'ch' (common abbreviation).
'speed' with its final letter taken away is 'spee'.
'spee'+'ch'='SPEECH'
(Other definitions for speech that I've seen before include "Formal spoken communication delivered to an audience" , "Oration, address" , "Speaking faculty" , "Communication by word of mouth" , "Vocal communication" .)