Lease in legal document taken out (7)
I believe the answer is:
deleted
'taken out' is the definition.
(deleting is a kind of taking out)
'lease in legal document' is the wordplay.
'lease' becomes 'let' ('let' can be a synonym of 'lease').
'in' means one lot of letters goes inside another.
'legal document' becomes 'deed' (deed is a kind of legal document).
'let' put into 'deed' is 'DELETED'.
(Other definitions for deleted that I've seen before include "Expunged" , "Struck out" , "Erased" , "Removed" , "Effaced" .)