Broad identification you and I must go without (4)
I believe the answer is:
wide
'broad' is the definition.
(I know that broad can be written as wide)
'identification you and i must go without' is the wordplay.
'identification' becomes 'ID' (abbreviation).
'you and i' becomes 'we'.
'must go without' means one lot of letters goes inside another (without can mean outside).
'id' going within 'we' is 'WIDE'.
(Other definitions for wide that I've seen before include "Extensive" , "Unplayable ball (cricket)" , "Of vast scope" , "(At cricket) an extra" , "Spacious; an extra" .)