initiate vs trainee

initiate and trainee both are nouns.

Word	Noun	Adjective	Verb	Adverb
initiate	Yes	No	Yes	No
trainee	Yes	No	No	No

As nouns, trainee is a hyponym of initiate; that is, trainee is a word with a more specific, narrower meaning than initiate:

initiate (noun)	trainee (noun)
people who have been introduced to the mysteries of some field or activity	someone who is being trained
someone who has been admitted to membership in a scholarly field
someone new to a field or activity

initiate (verb)	trainee (verb)
set in motion, start an event or prepare the way for
bring up a topic for discussion
take the lead or initiative in; participate in the development of
bring into being
accept people into an exclusive society or group, usually with some rite