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' (term for a study or office).
'wi'+'den'='WIDEN'
(Other definitions for widen that I've seen before include "Extend across" , "Make less narrow" , "Broaden - enlarge" , "Increase dimension" , "Spread" .)