Outstanding women contributed to dictionary (4)
I believe the answer is:
owed
'outstanding' is the definition.
('owed' can be a synonym of 'outstanding')
'women contributed to dictionary' is the wordplay.
'women' becomes 'w'.
'contributed to' indicates putting letters inside.
'dictionary' becomes 'oed' (Oxford English Dictionary).
'w' inserted within 'oed' is 'OWED'.
(Other definitions for owed that I've seen before include "to be paid" , "Outstanding" , "Had an obligation to pay" , "Was obliged to pay" , "In debt to" .)