Immersion

1. (n.) The act of immersing, or the state of being immersed; a sinking within a fluid; a dipping; as, the immersion of Achilles in the Styx.
2. (n.) Submersion in water for the purpose of Christian baptism, as, practiced by the Baptists.
3. (n.) The state of being overhelmed or deeply absorbed; deep engagedness.
4. (n.) The dissapearance of a celestail body, by passing either behind another, as in the occultation of a star, or into its shadow, as in the eclipse of a satellite; -- opposed to emersion.