1. administering the Christian sacrament of baptism to someone, typically by immersion in or sprinkling with water
Usage: present participle of baptise (British spelling; American spelling is baptizing); religious context
2. giving a name or nickname to someone or something; formally initiating or introducing
Usage: figurative or extended use

Examples

• The priest is baptising the newborn at the church this Sunday.
• They are baptising their daughter in the river according to their faith.
• The ceremony involves baptising infants with holy water.
• The ship was baptised with champagne before its maiden voyage.
• They are baptising the new community centre with a special dedication event.