In feudal society as well (4)
I believe the answer is:
also
'as well' is the definition.
(synonyms)
'in feudal society' is the wordplay.
'in' indicates a hidden word.
'ALSO' can be found hidden inside 'feudal society'.
(Other definitions for also that I've seen before include "Item" , "in accompaniment" , "on top" , "To boot" , "Old" .)