"to plunge into (a fluid)," early 15c. (implied in immersed), from Latin immersus, past participle of immergere "to plunge in, dip into, sink, submerge" (see immersion). Figuratively, of study, work, passion, etc., from 1660s. Related: Immersed; immersing; immersive.
He immersed himself into his studies
immense
immensely
immensity
immensurable
immerge
immerse
immersion
immigrant
immigrate
immigration
imminence