Old fellow left-winger is protected (7)
I believe the answer is:
covered
'protected' is the definition.
(covering is a kind of protecting)
'old fellow left-winger' is the wordplay.
'old fellow' becomes 'cove' (old-fashioned slang term).
'left-winger' becomes 'red' (red can mean a leftwing person).
'cove'+'red'='COVERED'
'is' acts as a link.
(Other definitions for covered that I've seen before include "given protection" , "Insured; enveloped" , "Concealed; dealt with" , "Overlaid with something" , "Travelled (a distance); protected" .)