No longer needed socialist and German worker (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 "getting P45?" , "No longer useful" , "Surplus to requirements" , "No longer required, unnecessary" , "unwanted" .)