/i merr"zheuhn, -sheuhn/ , n.
1. an act or instance of immersing.
2. state of being immersed.
3. state of being deeply engaged or involved; absorption.
4. baptism in which the whole body of the person is submerged in the water.
5. Also called ingress . Astron. the entrance of a heavenly body into an eclipse by another body, an occultation, or a transit. Cf. emersion (def. 1).
6. concentrating on one course of instruction, subject, or project to the exclusion of all others for several days or weeks; intensive: an immersion course in conversational French.
[ 1425-75; late ME immersion- (s. of immersio ) a dipping in. See IMMERSE, -ION ]