There's nothing left in the lift (3)
I believe the answer is:
nil
'there's nothing' is the definition.
(nil means a score of zero in football)
'left in the lift' is the wordplay.
'left' becomes 'l' (common abbreviation).
'the lift' indicates an anagram (I've seen 'lifts' mean this).
'l'+'in'='lin'
'lin' is an anagram of 'NIL'.
(Other definitions for nil that I've seen before include "Nothing, no score" , "Love" , "0" , "Lacking value" , "Nothing, zilch" .)