Socialist eating fish swayed (6)
I believe the answer is:
reeled
'swayed' is the definition.
(I've seen this in another clue)
'socialist eating fish' is the wordplay.
'socialist' becomes 'red' (socialism is often associated with the colour red).
'eating' is an insertion indicator.
'fish' becomes 'eel' (eel is a type of fish).
'red' placed around 'eel' is 'REELED'.
(Other definitions for reeled that I've seen before include "swam around" , "Staggered about in lively dance?" , "Felt giddy, staggered" , "Lurched" , "Staggered (at a Highland ball?)" .)