Which word refers to a formal process of welcoming someone into a group?

The term that best fits the description of a formal process of welcoming someone into a group is "induction." This word specifically refers to the ceremonial act of introducing or welcoming a new member into an organization, group, or position, often accompanied by specific rituals or formal procedures.

Induction ceremonies can be seen in various contexts, such as academic settings where students are inducted into honor societies, or in professional realms where new employees are officially welcomed into a company. This process often signifies that the individual now holds a recognized status within the group and that they have accepted the responsibilities and benefits of membership.

The other terms provided do not capture the essence of this formal welcoming process as precisely as "induction." Appointment refers to the act of assigning someone to a position but does not imply a ceremonial welcome. Reception might denote a gathering or event to welcome someone, but it lacks the formal structure associated with the process of induction. Integration suggests the absorption of someone into a group, but again, it does not convey the formal nature of the welcoming ceremony that "induction" provides.