Section of a contract (6)
I believe the answer is:
clause
'section of a contract' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for clause that I've seen before include "More than a phrase and not quite a sentence" , "Proviso" , "part of legal document" , "Part of a sentence with its own finite verb" , "Not quite a full sentence" .)