Socialist in surge shows weariness (7)
I believe the answer is:
boredom
'weariness' is the definition.
(thesaurus)
'socialist in surge' is the wordplay.
'socialist' becomes 'red' (socialism is often associated with the colour red).
'in' indicates putting letters inside.
'surge' becomes 'boom' (I can't explain this - if you can you should give a lot more credence to this answer).
'red' put within 'boom' is 'BOREDOM'.
'shows' is the link.
Can you help me to learn more?
(Other definitions for boredom that I've seen before include "Monotony" , "Overseers" , "Mental state" , "weary idleness" , "no interest" .)