shoal
n.n. a large group of fish swimming together in a tight, moving line. You often see them in the ocean or a lake.
n. a large group of fish swimming together in a coordinated formation. Often used in the context of marine biology or fishing.
The fishermen saw a large shoal of sardines.
The boat moved slowly through the shoal of silver fish that were feeding near the surface.
The migration of the shoal is a spectacular sight, as thousands of individuals move in perfect synchrony to reach their spawning grounds.
From Middle English schold, scholde, from Old English sċeald (“shallow”), perhaps from Proto-Germanic skalidaz, past participle of skaljaną (“to go dry, dry up, become shallow”), from skalaz (“parched, shallow”), from Proto-Indo-European (s)kelh₁- (“to dry out”). Cognate with Low German Scholl (“shallow water”), German schal (“stale, flat, vapid”). Compare shallow.
1570, presumably from Middle English schole (“school of fish”), from Old English sċeolu, sċolu (“troop or band of people, host, multitude, division of army, school of fish”), from Proto-West Germanic skolu, from Proto-Germanic skulō (“crowd”), from Proto-Indo-European (s)kelH- (“to divide, split, separate”). Cognate with West Frisian skoal (“shoal”), Middle Low German schōle (“multitude, troop”), Dutch school (“shoal of fishes”). Doublet of school.