City once a small part of London? (7)
I believe the answer is:
babylon
'city once' is the definition.
(I've seen this before)
'a small part of london?' is the wordplay.
'a small' becomes 'baby'.
'part of london?' becomes 'lon' (I can't justify this - if you can you should give a lot more credence to this answer).
'baby'+'lon'='BABYLON'
Can you help me to learn more?
(Other definitions for babylon that I've seen before include "Ancient capital" , "Place of sorrowful exile (or of luxury and decadence)" , "Sinful city in Biblical times, had Hanging Gardens" , "Wicked city of the Bible, on Euphrates river in central Iraq" , "Bony lab found in the ancient city" .)