immersed

Adjective

immersed (comparative more immersed, superlative most immersed)

1. Under the surface of a liquid; sunk.
2. (figuratively) 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.1927, Ernest Bramah [pseudonym; Ernest Brammah Smith], Max Carrados Mysteries
   • 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; […].1964 July, “New Books”, in Modern Railways, page 74
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.