Be an outsider no longer (5)
I believe the answer is:
enter
'be' is the definition.
(entering is a kind of being)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for enter that I've seen before include "Come in - penetrate - record" , "Get in" , "Enroll, sign up" , "Go in - set down" , "Inscribe" .)