Reject good European composer (5)
I believe the answer is:
binge
'composer' is the definition.
Although both the answer and definition are singular nouns, I don't see how they can define each other.
'reject good european' is the wordplay.
'reject' becomes 'bin' (I've seen this in other clues).
'good' becomes 'g' (abbreviation).
'european' becomes 'E' (abbreviation e.g. EU).
'bin'+'g'+'e'='BINGE'
Can you help me to learn more?
(Other definitions for binge that I've seen before include "Indulge too much" , "Bout of indulgence" , "Indulgent spree" , "Prolonged drinking session" , "Bender" .)