Insurance is about finished (5)
I believe the answer is:
cover
'insurance' is the definition.
(thesaurus)
'about finished' is the wordplay.
'about' becomes 'c' (abbreviation for 'circa').
'finished' becomes 'over' ('over' can be similar in meaning to 'finished').
'c'+'over'='COVER'
'is' acts as a link.
(Other definitions for cover that I've seen before include "(Put) lid (on) - fielding position - insurance" , "Overlay" , "Sit on - suffice for" , "Enshroud" , "Totally obscure" .)