initiation
A special process for starting or joining something important.
Initiation is the process of beginning something new or being formally welcomed into a group. When you join a club, team, or organization, your initiation might involve learning special handshakes, traditions, or responsibilities that members share. Ancient societies had initiation ceremonies marking when young people became adults. Modern examples include earning your black belt in karate after years of training or becoming an Eagle Scout after completing all the requirements.
When you initiate something, you're the one starting it: a teacher might initiate a class discussion, or a student might initiate a new recycling program at school.
In stories and history, initiation often means proving yourself worthy. Medieval squires went through years of initiation before becoming knights. Today, new team members might go through an initiation period where they learn how things work before becoming full participants.
The word carries a sense of crossing a threshold from outsider to insider, from beginner to member. Initiations help newcomers feel welcomed and teach them what they need to know. They mark important transitions.