Communist annoyed humanitarian organisation
I believe the answer is:
red cross
'humanitarian organisation' is the definition.
(I've seen this before)
'communist annoyed' is the wordplay.
'communist' becomes 'red' (red is a kind of communist).
'annoyed' becomes 'cross' (I've seen this before).
'red'+'cross'='RED-CROSS'
(Other definitions for red cross that I've seen before include "Medical outfit" , "International organisation for helping war-wounded" , "International humanitarian organisation" , "Famous emblem" , "Medical group" .)