Painful look given by wife in church (5)
I believe the answer is:
wince
'painful look' is the definition.
(facial expression made when in pain)
'by wife in church' is the wordplay.
'by' means one lot of letters go next to another.
'wife' becomes 'w'.
'church' becomes 'ce' (abbreviation for Church of England).
'w'+'in' is 'win'.
'win'+'ce'='WINCE'
'given' acts as a link.
(Other definitions for wince that I've seen before include "Start painfully" , "Flinch with pain" , "Cringe" , "Pull a face" , "Make face showing pain" .)