initiate
US /ɪˈnɪʃ.i.eɪt/
UK /ɪˈnɪʃ.i.eɪt/

1.
1.
a person who has been initiated into a secret society or group
:
•
The new initiate was eager to learn the group's traditions.
•
Only an initiate can understand the hidden meanings.
a person who has been initiated into a secret society or group