christening vs immersion

christening

noun
  • The Christian sacrament at which someone, usually a child, is baptized and given a Christian name. 

  • Any instance of someone's or something's being christened. 

immersion

noun
  • The total submerging of a person in water as an act of baptism. 

  • The disappearance of a celestial body, by passing either behind another, as in the occultation of a star, or into its shadow, as in the eclipse of a satellite. 

  • An immersion heater. 

  • A smooth map whose differential is everywhere injective, related to the mathematical concept of an embedding. 

  • One's suspension of disbelief while reading, playing a video game, etc. The experience of losing oneself in a fictional world. 

  • Deep engagement in something. 

  • A form of foreign-language teaching where the language is used intensively to teach other subjects to a student. 

How often have the words christening and immersion occurred in a corpus of books? (source: Google Ngram Viewer )