Furious, judge on island (5)
I believe the answer is:
irate
'furious' is the definition.
(thesaurus)
'judge on island' is the wordplay.
'judge' becomes 'rate' (rating is a kind of judging).
'on' says to put letters next to each other.
'island' becomes 'i'.
'rate' put after 'i' is 'IRATE'.
(Other definitions for irate that I've seen before include "Wild" , "Ticked off" , "raging" , "Hacked off" , "Annoyed, exasperated" .)