Socialist worker gets German and unnecessary (9)
I believe the answer is:
redundant
'unnecessary' is the definition.
(similar in meaning)
'socialist worker gets german and' is the wordplay.
'socialist' becomes 'red' (socialism is often associated with the colour red).
'worker' becomes 'ant' (worker is a type of ant).
'gets' is an insertion indicator (gets can mean captures or absorbs).
'german and' becomes 'und' ('and' in German).
'red'+'ant'='redant'
'redant' enclosing 'und' is 'REDUNDANT'.
(Other definitions for redundant that I've seen before include "laid off" , "no longer wanted" , "no longer needed" , "getting P45?" , "without useful purpose" .)