baptism

a Christian sacrament signifying spiritual cleansing and rebirth; "most churches baptize infants but some insist on adult baptism"

• affusion — the act of baptizing someone by pouring water on their head
• aspersion, sprinkling — the act of sprinkling water in baptism (rare)
• immersion — a form of baptism in which part or all of a person's body is submerged
• christening — giving a Christian name at baptism

• sacrament — a formal religious act conferring a specific grace on those who receive it