Socialist and German worker no longer needed (9)
I believe the answer is:
redundant
'no longer needed' is the definition.
(I've seen this before)
'socialist and german worker' is the wordplay.
'socialist' becomes 'red' (red can informally mean a socialist).
'and german' becomes 'und' ('and' in German).
'worker' becomes 'ant' (worker is a type of ant).
'red'+'und'+'ant'='REDUNDANT'
(Other definitions for redundant that I've seen before include "No longer necessary" , "no longer wanted" , "without useful purpose" , "getting P45?" , "unwanted" .)