If returning to church take high-class shawl (5)
I believe the answer is:
fichu
'shawl' is the definition.
(I've seen this before)
'if returning to church take high-class' is the wordplay.
'returning' says the letters should be written backwards.
'to church' becomes 'ch' (common abbreviation).
'take' says to put letters next to each other.
'high class' becomes 'U' (as in U and non-U speech).
'if' in reverse letter order is 'fi'.
'fi'+'ch'+'u'='FICHU'
(Other definitions for fichu that I've seen before include "Triangular piece of muslin for the neck" , "Cloth triangle" , "Light triangular scarf" , "Triangular cape" , "Woman's small shawl or scarf" .)