Permit put on phone lock (7)
I believe the answer is:
ringlet
'lock' is the definition.
(thesaurus)
'permit put on phone' is the wordplay.
'permit' becomes 'let' ('let' can be a synonym of 'permit').
'put on' is a charade indicator (letters next to each other).
'phone' becomes 'ring' ('ring' can be a synonym of 'phone').
'let' after 'ring' is 'RINGLET'.
(Other definitions for ringlet that I've seen before include "Hair curl, of an Irish dancer perhaps" , "Long curl of hair" , "Cluster of hair" , "Curl of hair; butterfly" , "Curling lock of hair" .)