Ancient city adopting female doorkeeper (5)
I believe the answer is:
usher
'doorkeeper' is the definition.
(I know that doorkeeper can be written as usher)
'ancient city adopting female' is the wordplay.
'ancient city' becomes 'ur' (ancient Sumerian city state).
'adopting' indicates putting letters inside (inserted letters are taken on or adopted).
'female' becomes 'she' ('she' refers to a woman).
'ur' going around 'she' is 'USHER'.
(Other definitions for usher that I've seen before include "whose house collapsed?" , "Doorkeeper, escort" , "Guide at wedding" , "He shows people to their seats in theatre" , "Theatre/cinema worker" .)