immersion
Pronunciation: /ɪˈməːʃ(ə)n/
noun
- 1the action of immersing someone or something in a liquid: his back was still raw from immersion in the icy Atlantic sea
- baptism by immersing a person bodily (but not necessarily completely) in water.

Origin:
late 15th century: from late Latin immersio(n-), from immergere 'dip into' (see immerse)