Chairman devouring last of curry sauce (4)
I believe the answer is:
mayo
'sauce' is the definition.
'chairman devouring last of curry' is the wordplay.
'chairman' becomes 'Mao' (Chinese leader Chairman Mao).
'devouring' means one lot of letters goes inside another.
'last of' suggests the final letters.
The final letter of 'curry' is 'y'.
'mao' placed around 'y' is 'MAYO'.
(Other definitions for mayo that I've seen before include "radio presenter" , "Cold, creamy sauce (abbr)" , "Irish county - sauce (abbr)" , "Irish county (county town, Castlebar)" , "Eg, Braeburn or Cox" .)