immersion
noun
[ ɪˈməːʃ(ə)n ]
• the action of immersing someone or something in a liquid.
• "his back was still raw from immersion in the icy Atlantic sea"
• deep mental involvement in something.
• "a week's immersion in the culinary heritage of Puglia"
• the disappearance of a celestial body in the shadow of or behind another.
Origin:
late 15th century: from late Latin immersio(n- ), from immergere ‘dip into’ (see immerse).