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.-submersion in water for the purpose of christian baptism, as, practiced by the baptists.-the state of being overhelmed or deeply absorbed; deep engagedness.-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.