Nouns

(n)submergence, submerging, submersion, immersionsinking until covered completely with water
(n)ingress, immersion(astronomy) the disappearance of a celestial body prior to an eclipse
(n)concentration, engrossment, absorption, immersioncomplete attention; intense mental effort
(n)immersiona form of baptism in which part or all of a person's body is submerged
(n)submersion, immersion, ducking, dousingthe act of wetting something by submerging it