City built is fantastic one displacing upper-class (7)
I believe the answer is:
tbilisi
'city' is the definition.
(I've seen this before)
'built is fantastic one displacing upper-class' is the wordplay.
I cannot quite understand how this works, but
'is' is within the answer.
'one' could be 'i' (Roman numeral) and 'i' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for tbilisi that I've seen before include "Georgian city" , "Georgian place" , "Georgian capital" , "Capital city of Georgia" .)