Permit everyone to be in debt endlessly (5)
I believe the answer is:
allow
'permit' is the definition.
('allow' can be a synonym of 'permit')
'everyone to be in debt endlessly' is the wordplay.
'everyone' becomes 'all' (I've seen this before).
'to be in debt' becomes 'owe' (I've seen this before).
'endlessly' means to remove the last letter.
'owe' with its final letter taken away is 'ow'.
'all'+'ow'='ALLOW'
(Other definitions for allow that I've seen before include "Acknowledge - concede" , "Grant" , "Permit or concede" , "Permit, let happen" , "Tolerate" .)