There's nothing in raising the blind (3)
I believe the answer is:
nil
'there's nothing' is the definition.
(nil means a score of zero in football)
'in raising the blind' is the wordplay.
'raising' is a reversal indicator (in a down clue, letters go up).
'in' indicates a hidden word.
'lin' can be found hidden inside 'blind'.
'lin' back-to-front is 'NIL'.
(Other definitions for nil that I've seen before include "none" , "Lacking value" , "Nothing, zilch" , "Nothing, no score" , "Don't despair - . . . desperandum" .)