High spirits in Brussels over four we hear — no case for bias (8)
I believe the answer is:
euphoria
'high spirits' is the definition.
(I've seen this in another clue)
'brussels over four we hear no case for bias' is the wordplay.
I cannot quite see how this works, but
'brussels' could be 'eu' (European Parliament is based in Brussels) and 'eu' is found within the answer.
'over' could be 'o' (cricket abbreviation) and 'o' is found within the answer.
This explanation may well be incorrect...
'in' acts as a link.
Can you help me to learn more?
(Other definitions for euphoria that I've seen before include "Sense of wellbeing" , "Jubilation" , "Great happiness and exhilaration" , "Irrational high" , "transport" .)