He's left out, almost (3)
I believe the answer is:
lou
'he's' is the definition.
'left out almost' is the wordplay.
'left' becomes 'l' (common abbreviation).
'almost' means to remove the last letter (almost the whole word is kept).
'out' with its last letter taken off is 'ou'.
'l'+'ou'='LOU'
(Other definitions for lou that I've seen before include "-- Costello, Abbott's partner" , "man" , "-- Reed, singer" , "-- Reed, rock musician" , "Male or female" .)