Communist swallowing fish eye (6)
I believe the answer is:
regard
'eye' is the definition.
(thesaurus)
'communist swallowing fish' is the wordplay.
'communist' becomes 'red' (red can informally mean communist).
'swallowing' is an insertion indicator.
'fish' becomes 'gar' (type of fish).
'red' enclosing 'gar' is 'REGARD'.
(Other definitions for regard that I've seen before include "Watch" , "Former gold coin" , "Attitude of admiration or esteem" , "Concern" , "Look - respect" .)