Unusually quiet metropolitan in the EU seems to be always moving (9,6)
I believe the answer is:
perpetual motion
'always moving' is the definition.
The definition suggests a singular noun which matches the answer.
'unusually quiet metropolitan in the eu seems' is the wordplay.
I cannot really understand how this works, but
'quiet' could be 'p' (music symbol for 'piano', ie soft or quiet) and 'p' is located in the answer.
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is found in the answer.
'eu' is found in the answer.
This may be the basis of the clue (or it may be nonsense).
'to be' acts as a link.
Can you help me to learn more?
(Other definitions for perpetual motion that I've seen before include "that keeps on going" , "Always going" .)