initiate
To begin; to start.
To instruct in the rudiments or principles; to introduce.
To confer membership on; especially, to admit to a secret order with mysterious rites or ceremonies.
To do the first act; to perform the first rite; to take the initiative.
(new member of an organization) A new member of an organization.
(one who has been through a ceremony of initiation) One who has been through a ceremony of initiation.
(one who is knowledgeable and experienced in a topic) One who is (oriented#Adjective) in and (familiar#Adjective) with a topic or subject; especially, one who is an (expert#Noun) in it.
(obsolete) Unpracticed, untried, new.
(obsolete) Begun, commenced, introduced to or in the rudiments (of), newly admitted.