One putting out European champion (7)
I believe the answer is:
evictor
'one putting' is the definition.
The definition suggests a singular noun which matches the answer.
'european champion' is the wordplay.
'european' becomes 'e' (abbreviation e.g. EU).
'champion' becomes 'victor' (I've seen this before).
'e'+'victor'='EVICTOR'
'out' acts as a link.
Can you help me to learn more?
(Other definitions for evictor that I've seen before include "One turning out" , "Nightclub bouncer?" , "One chucks out" , "He may put out" , "who puts an end to occupation?" .)