Transport chief playing for money (7)
I believe the answer is:
busking
'playing for money' is the definition.
(to busk is to play music for money)
'transport chief' is the wordplay.
'transport' becomes 'bus' (bus is a kind of transport).
'chief' becomes 'king'.
'bus'+'king'='BUSKING'
(Other definitions for busking that I've seen before include "Performing in the street for money" , "Serenading passers-by" , "Playing street music" , "providing entertainment for commuters?" , "performing for donations" .)