Useless and, for Marx, boring socialist worker, say (9)
I believe the answer is:
redundant
'useless' is the definition.
Both the definition and answer are adjectives. Maybe there's a link between them I don't understand?
'for marx boring socialist worker say' is the wordplay.
'for marx' becomes 'dun' (I can't justify this - if you can you should believe this answer much more).
'boring' is an insertion indicator (to bore something can mean to drill into it).
'socialist' becomes 'red' (red can informally mean a socialist).
'worker say' becomes 'ant' (worker is a type of ant).
'dun' placed inside 'red' is 'redund'.
'redund'+'ant'='REDUNDANT'
'and' is the link.
Can you help me to learn more?
(Other definitions for redundant that I've seen before include "Superfluous to requirements" , "Surplus to requirements" , "No longer necessary" , "unwanted" , "No longer required, unnecessary" .)