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' (I've seen this before) and 'fee' is present in the remaining letters.
This accounts for all the letters.
This may be the basis of clue (or it may be nonsense).
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" .)