Potentially, exams for American agents learner passes to get headgear (7)
I believe the answer is:
fedoras
'potentially exams for american agents' is the definition.
I can't judge whether this definition defines the answer.
'learner passes to get headgear' is the wordplay.
'learner passes' becomes 's' (I am not sure about this - if you are sure you should believe this answer much more).
'to get' says to put letters next to each other.
'headgear' becomes 'fedora' (fedora is a kind of headgear).
's' after 'fedora' is 'FEDORAS'.
Can you help me to learn more?
(Another definition for fedoras that I've seen is " Felt hats with creased crowns".)