Wealthy male curbing European seat of power (9)
I believe the answer is:
reichstag
'seat of power' is the definition.
The definition suggests a singular noun which matches the answer.
'wealthy male curbing european' is the wordplay.
I cannot quite see how this works, but
'male' could be 'stag' (a stag is a male deer) and 'stag' is located in the answer.
'european' could be 'e' (abbreviation e.g. EU) and 'e' is present in the answer.
'wealthy' could be 'rich' (similar in meaning) and 'rich' is located in the leftover letters.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for reichstag that I've seen before include "old German house" , "diet in Germany" , "Berlin parliamentary building" , "Continental diet" , "Berlin building burnt in 1933" .)