Communist studied in speech (3)
I believe the answer is:
red
'communist' is the definition.
(red is a kind of communist)
'studied in speech' is the wordplay.
'studied' becomes 'read' (I've seen this before).
'in speech' shows a homophone (sound like).
'read' sounds like 'RED'.
(Other definitions for red that I've seen before include "Colour of Merlot wine" , "Florid" , "Bloodshot" , "Bordeaux claret, for instance" , "Scarlet or vermilion" .)