City in ascendant or on top (7)
I believe the answer is:
toronto
'city' is the definition.
(Toronto is an example)
'in ascendant or on top' is the wordplay.
'in' indicates the answer is hidden within the clue.
'TORONTO' is hidden within 'ascendant or on top'.
(Other definitions for toronto that I've seen before include "Ontarian capital" , "Transatlantic city" , "place on Lake Ontario" , "Provincial capital" , "Ontario's capital" .)