Dynasty to toil inside the city (5)
I believe the answer is:
hanoi
'the city' is the definition.
(Hanoi is an example)
'dynasty to toil inside' is the wordplay.
'dynasty' becomes 'han' (I've seen this before).
'inside' means to look at the middle letters.
The centre of 'toil' is 'oi'.
'han'+'oi'='HANOI'
(Other definitions for hanoi that I've seen before include "Vietnamese capital" , "Vietnamese city" , "Asian city" , "Asian capital on the Red River" , "capital out East" .)