Free former politician and French guards (6)
I believe the answer is:
exempt
'free' is the definition.
(I know that exempt is a type of free)
'former politician and french guards' is the wordplay.
'former' becomes 'ex' (prefix meaning former or onetime).
'politician' becomes 'MP' (Member of Parliament).
'and french' becomes 'et' ('and' in the French language).
'guards' indicates putting letters inside (inserted letters are guarded).
'mp' put into 'et' is 'empt'.
'ex'+'empt'='EXEMPT'
(Other definitions for exempt that I've seen before include "Release" , "Not liable, as others may be" , "Not subject to a law" , "Absolve, excuse" , "may mean the taxman may ignore some charge" .)