Start to chase a red squirrel away (5)
I believe the answer is:
cache
'squirrel away' is the definition.
(synonyms)
'start to chase a red' is the wordplay.
'start to' says to take the initial letters.
'red' becomes 'che' (Che Guevara the Marxist revolutionary).
The first letter of 'chase' is 'c'.
'c'+'a'+'che'='CACHE'
(Other definitions for cache that I've seen before include "Hidden storage space" , "Hidden store of things" , "Hidden storage place" , "Put away" , "Secret store of valuables" .)