Question

Originally an adjective, it's now a noun referring to a deep-sea vessel like a submarine or bathyscaphe.

a) Abyssal
b) Aquatic
c) Maritime
d) Subterranean

Answer 1

The term 'abyssal' originally described oceanic depths but now also refers to deep-sea vessels like submarines.

Step-by-step explanation:

The noun in question that refers to a deep-sea vessel, like a submarine or bathyscaphe, is abyssal. This term was originally used as an adjective to describe the abyssal zone, the deepest part of the ocean at depths of 4000 m or greater, where conditions are extremely cold and high pressure with high oxygen and low nutrient content. Over time, 'abyssal' has come to refer to vessels designed for deep-sea exploration which operate in this challenging environment.