All 4 Uses of

initiate
in
A Great and Terrible Beauty

A little initiation ceremony for new girls who might prove worthy of our inner circle.
Chpt 7

initiation = acceptance of membership

So, what is this secret initiation?
Chpt 7 *

initiation = process or ceremony (to accept new members)

It's just a little initiation we have here at Spence—we like to torture each other.
Chpt 7

Once Felicity has her drink, we've all been initiated.
Chpt 13

initiated = accepted as a members through special procedures

Definitions:

(1) (initiate as in: initiate discussions)
to cause (something) to begin
(2) (initiate as in: initiate into the art of drumming)
introduce to an activity or area of knowledge
(3) (initiate as in: initiate into the fraternity)
to accept someone's membership into an organization -- typically in a ceremony -- sometimes including a period of instruction and/or test
(4) (initiate as in: She is a new initiate.)
someone who has formally started in an organization, or been introduced to or attained some expertise in a particular field