immersed

adj

1. Under the surface of a liquid; sunk.
2. Deeply involved.

   “At a suitable distance apart, exercising his unique gift of being profoundly impressed by a subject that he had no interest in whatever, Parkinson was deeply immersed in a chart illustrating a century of wheat averages of the British Isles.”

   “ON THE NARROW GAUGE. By P. B. Whitehouse. Nelson 30s. […] In an introductory note Mr. Whitehouse disarms any criticism from narrow-gauge aficionados as immersed in the subject as himself by pointing out that his book has no pretensions to the status of a new narrow-gauge textbook; […].”

3. Lowered or sunken relative to a reference surface.

   “Sori in the axils of lamina branches, partly immersed; involucre bell- or trumpet-shaped, or obconical, usually 2-lipped; receptacle generally exserted.”

verb

1. (form-of, participle, past)simple past and past participle of immerse