Unworried about a heartless judge (8)
I believe the answer is:
carefree
'unworried' is the definition.
('carefree' can be a synonym of 'unworried')
'about a heartless judge' is the wordplay.
'about' becomes 'ca' (abbreviation for 'circa').
'a heartless' suggests removing the centre.
'judge' becomes 'referee' (refereeing is a kind of judging).
'referee' with its middle removed is 'refree'.
'ca'+'refree'='CAREFREE'
(Other definitions for carefree that I've seen before include "Free of trouble and worry" , "relaxed" , "Light-hearted, no worries" , "Not worried" , "Without worry or responsibility" .)