A dean's original sermon maybe in worship (9)
I believe the answer is:
adoration
'worship' is the definition.
(adoration can mean worship or devotion)
'a dean's original sermon maybe' is the wordplay.
'original' suggests taking the first letters.
'sermon maybe' becomes 'oration' (a sermon is a type of oration or speech).
The initial letter of 'deans' is 'd'.
'a'+'d'+'oration'='ADORATION'
'in' acts as a link.
(Other definitions for adoration that I've seen before include "Great affection" , "What star gets from fans" , "high regard" , "high esteem" , "praise" .)