Before revision: In English usage, the word sound refers to an inlet that is deeper than a bight and wider than a fjord; and refers to a narrow sea channel or an ocean channel between two land masses, such as a strait; and also refers to the lagoon between a barrier island and the mainland.
After revision: A sound may be an inlet that is deeper than a bight and wider than a fjord; or a narrow sea channel or an ocean channel between two land masses, such as a strait; or also a lagoon between a barrier island and the mainland.