Meaning of “initiate” - Learner’s Dictionary

initiate

verb [ T ] uk us /ɪˈnɪʃieɪt/
START

to make something begin:

[ often passive ] The program was initiated by the state government.
JOIN

to make someone a member of a group or organization in a special ceremony, or to show someone how to do an activity:

At the age of 50, he was initiated into the priesthood.
initiation uk us /ɪˌnɪʃiˈeɪʃən/ noun [ C, U ]

(Definition of “initiate” from the Cambridge Learner’s Dictionary © Cambridge University Press)