noun.
A great multitude; a crowd; a throng; of fish, a school: as, a shoal of herring; shoals of people.
To assemble in a multitude; crowd; throng; school, as fish.
To become shallow, or more shallow.
Nautical, to cause to become shallow, or more shallow; proceed from a greater into a lesser depth of: as, a vessel in sailing shoals her water.
Shallow; of little depth.
noun.
A place where the water of a stream, lake, or sea is of little depth; a sand-bank or bar; a shallow; more particularly, among seamen, a sand-bank which shows at low water: also used figuratively.