Guide the woman inside old city (5)
I believe the answer is:
usher
'guide' is the definition.
(an usher guides people)
'woman inside old city' is the wordplay.
'woman' becomes 'she' ().
'inside' indicates putting letters inside.
'old city' becomes 'ur' (ancient city state).
'she' inserted within 'ur' is 'USHER'.
'the' is the link.
(Other definitions for usher that I've seen before include "Doorkeeper in parliament or 29 down" , "He shows people to their seats in theatre" , "Cinema or wedding attendant" , "One puts you in your place" , "Minor court official" .)