Initiation is a rite of passage

Rite of passage

A rite of passage is a ritual event that marks a person's progress from one status to another. It is a universal phenomenon which can show anthropologists what social hierarchies, values and beliefs are important in specific cultures....

 ceremony

Ceremony

A ceremony is an event of ritual significance, performed on a special occasion. The word may be of Etruscan origin.-Ceremonial occasions:A ceremony may mark a rite of passage in a human life, marking the significance of, for example:* birth...

 marking entrance or acceptance into a group or society. It could also be a formal admission to adulthood in a community or one of its formal components. In an extended sense it can also signify a transformation in which the initiate is 'reborn' into a new role.

Examples of initiation ceremonies might include Hindu diksha

Diksha

Diksa also spelled deeksha or deeksa in common usage, translated as a "preparation or consecration for a religious ceremony", is giving of a mantra or an initiation by the guru in Indian religions such as Hinduism, Buddhism, and Jainism...

, Christian baptism

Baptism

In Christianity, baptism is for the majority the rite of admission , almost invariably with the use of water, into the Christian Church generally and also membership of a particular church tradition...

 or confirmation

Confirmation (Christian sacrament)

Confirmation is a rite of initiation in Christian churches, normally carried out through anointing and/or the laying on of hands and prayer for the purpose of bestowing the Gift of the Holy Spirit....

, Jewish bar or bat mitzvah

B'nai Mitzvah

Bar Mitzvah and Bat Mitzvah are Jewish coming of age rituals. According to Jewish law, when Jewish boys reach 13, they become responsible for their actions and become a Bar Mitzvah . The age for girls is 12...

, acceptance into a fraternal organization, secret society

Secret society

A secret society is a club or organization whose activities and inner functioning are concealed from non-members. The society may or may not attempt to conceal its existence. The term usually excludes covert groups, such as intelligence agencies or guerrilla insurgencies, which hide their...

 or religious order

Religious order

A religious order is a lineage of communities and organizations of people who live in some way set apart from society in accordance with their specific religious devotion, usually characterized by the principles of its founder's religious practice. The order is composed of initiates and, in some...

, or graduation

Graduation

Graduation is the action of receiving or conferring an academic degree or the ceremony that is sometimes associated, where students become Graduates. Before the graduation, candidates are referred to as Graduands. The date of graduation is often called degree day. The graduation itself is also...

 from school or recruit training

Recruit training

Recruit training, more commonly known as Basic Training and colloquially called Boot Camp, is the initial indoctrination and instruction given to new military personnel, enlisted and officer...

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A person taking the initiation ceremony in traditional rites, such as those depicted in these pictures, is called an initiate or initiand.
The English word derives from the Latin

Latin

Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

, initium: "entrance" or "beginning," literally "a going in." The related English verb, "initiate", means to begin or start a particular action, event, circumstance

Circumstance

- Legal terms :* Aggravating circumstance* Attendant circumstance, a legal concept which Black's Law Dictionary defines as the "facts surrounding an event."* Exigent circumstance* Extenuating circumstances- Films :...

, or happening

Happening

A happening is a performance, event or situation meant to be considered art, usually as performance art. Happenings take place anywhere , are often multi-disciplinary, with a nonlinear narrative and the active participation of the audience...

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A spiritual initiation rite normally implies a shepherding process where those who are at a higher level guide the initiate through a process of greater exposure of knowledge.