Initiation, n.
Etymology: [L. initiatio: cf. F. initiation.]
1. The act of initiating, or the process of being initiated or introduced; as, initiation into a society, into business, literature, etc. "The initiation of coursers of events." Pope.
2. The form or ceremony by which a person is introduced into any society; mode of entrance into an organized body; especially, the rite of admission into a secret society or order. Silence is the first thing that is taught us at our initiation into sacred mysteries. Broome.
Shades of meaning
Fernald has no entry of its own for initiation; he lists it under beginning.
He lists it without comment; the entries above explain its neighbors.