Having left payment out, do a bunk (4)
I believe the answer is:
flee
'a bunk' is the definition.
(thesaurus)
'having left payment out do' is the wordplay.
I cannot quite see how this works, but
'left' could be 'l' (common abbreviation) and 'l' is found within the answer.
'payment' could be 'fee' (payment for a job) and 'fee' is located in the leftover letters.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for flee that I've seen before include "Take flight" , "head for the hills" , "Abscond" , "retreat" , "rush" .)