Pronunciation: (i-mûr'zhun, -shun),[key] —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).
—adj. 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.