Calm priest introduced to half-cut reverend (7)
I believe the answer is:
'calm' is the definition.
'priest introduced to half-cut reverend' is the wordplay.
'priest' becomes 'eli' (biblical figure).
'introduced to' is an insertion indicator.
'half cut' means to take half the letters.
'reverend' cut in half is 'reve'.
'eli' put within 'reve' is 'RELIEVE'.
(Other definitions for relieve that I've seen before include "Soothe" , "Ease pain or burden" , "Comfort" , "Take over work from someone" , "Alleviate 9pain)" .)