Playing tune in car is risky (9)
I believe the answer is:
uncertain
'risky' is the definition.
(thesaurus)
'playing tune in car' is the wordplay.
'playing' indicates anagramming the letters.
'tune'+'in'+'car'='tuneincar'
'tuneincar' with letters rearranged gives 'UNCERTAIN'.
'is' is the link.
(Other definitions for uncertain that I've seen before include "Changeable" , "up in the air" , "Not convinced" , "Lacking confidence" , "Unsure" .)