Limit old women's fund (5)
I believe the answer is:
endow
'fund' is the definition.
(I've seen this before)
'limit old women's' is the wordplay.
'limit' becomes 'end' (I've seen this before).
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'women' becomes 'w'.
'end'+'o'+'w'='ENDOW'
(Other definitions for endow that I've seen before include "Provide with a permanent income - perhaps a college" , "Enrich (with a facility or gift)" , "Provide (with financial support, qualities etc)" , "Give money to" , "Establish (university post) by giving funds" .)