A legal document requiring action (4)
I believe the answer is:
This clue is a double definition.
'a legal document' is the first definition.
(I know that deed is a type of legal document)
'action' is the second definition.
(deed is a kind of action)
'requiring' acts as a link.
(Other definitions for deed that I've seen before include "Act - exploit - legal document" , "Heroic exploit" , "Feat" , "Action - legal document" , "Intentional action" .)