Expand women's group study (5)
I believe the answer is:
widen
'expand' is the definition.
(I've seen this before)
'women's group study' is the wordplay.
'women's group' becomes 'wi' (Women's Institute).
'study' becomes 'den' (den can mean an office or study).
'wi'+'den'='WIDEN'
(Other definitions for widen that I've seen before include "Extend across" , "Make less narrow" , "Broaden - enlarge" , "Increase dimension" , "Spread" .)