Permit produced by tense wife leaving gate (6)
I believe the answer is:
ticket
'permit' is the definition.
(I've seen this before)
'tense wife leaving gate' is the wordplay.
'tense' becomes 't' (abbreviation used in many dictionaries).
'wife' becomes 'w'.
'leaving' suggests deleting specific letters.
'gate' becomes 'wicket' (wicket gate is a kind of gate).
'wicket' with 'w' removed is 'icket'.
't'+'icket'='TICKET'
'produced by' is the link.
(Other definitions for ticket that I've seen before include "Token for entry" , "It entitles the bearer, to enter perhaps" , "Authority to travel" , "Document for traveller" , "Tag showing payment of fee" .)