Drug dealer not starting as escort (5)
I believe the answer is:
usher
'escort' is the definition.
(I know that usher is a type of escort)
'drug dealer not starting' is the wordplay.
'drug dealer' becomes 'pusher' (someone who sells or pushes drugs).
'not starting' means to remove the first letter.
'pusher' with its initial letter removed is 'USHER'.
'as' acts as a link.
(Other definitions for usher that I've seen before include "Show to seat" , "One who shows people to seats" , "Show in - escort" , "Escort (to a seat)" , "Person showing one to a seat" .)