Shows the clergyman is having a jumble sale (7)
I believe the answer is:
reveals
'shows' is the definition.
(revealing is a kind of showing)
'the clergyman is having a jumble sale' is the wordplay.
'the clergyman' becomes 'rev' (I've seen this before).
'is having' is a charade indicator (letters next to each other).
'a jumble' is an anagram indicator.
'sale' anagrammed gives 'eals'.
'rev'+'eals'='REVEALS'
(Other definitions for reveals that I've seen before include "Unmasks" , "Shows" , "Upright sides of doors and windows" , "Several (anag)" , "Divulges" .)