Socialist almost put on suit to get response (8)
I believe the answer is:
reaction
'response' is the definition.
(synonyms)
'socialist almost put on suit' is the wordplay.
'socialist' becomes 'red' (socialism is often associated with the colour red).
'almost' means to remove the last letter (almost the whole word is kept).
'put on' is a charade indicator (letters next to each other).
'suit' becomes 'action' (synonyms).
'red' with its last letter removed is 're'.
're'+'action'='REACTION'
'to get' acts as a link.
(Other definitions for reaction that I've seen before include "Chemical change or response" , "counter-revolution" , "Response to stimulus from creation" , "Result of stimulus" , "Creation found in response to event" .)