One judge is far from happy (5)
I believe the answer is:
irate
'far from happy' is the definition.
I can't judge whether this defines the answer.
'one judge' is the wordplay.
'one' becomes 'I' (Roman numeral).
'judge' becomes 'rate' (rating is a kind of judging).
'i'+'rate'='IRATE'
'is' is the link.
Can you help me to learn more?
(Other definitions for irate that I've seen before include "ranting" , "Angry, enraged" , "Ticked off" , "Annoyed, irritated" , "Wrathful" .)