shoal

Etymology 1

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.

adj

1. (now rare) Shallow.
   shoal water
   But that part of the coast being shoal and bare, / And rough with reefs which ran out many a mile, / His port lay on the other side o' the isle. 1819, Lord Byron, Don Juan, III.19

noun

1. A sandbank or sandbar creating a shallow.
   'Twas early June, the new grass was flourishing everywheres, the posies in the yard—peonies and such—in full bloom, the sun was shining, and the water of the bay was blue, with light green streaks where the shoal showed. 1913, Joseph C. Lincoln, chapter 1, in Mr. Pratt's Patients
2. A shallow in a body of water.

verb

1. To arrive at a shallow (or less deep) area.
2. (transitive) To cause a shallowing; to come to a more shallow part of.
   Noting the rate at which she shoals her water -[…] 1859, Matthew Fontaine Maury, Explanations and Sailing Directions to Accompany the Wind and Current Charts
3. To become shallow.
   The colour of the water shows where it shoals.

Etymology 2

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.

noun

1. Any large number of persons or things.
2. (collective) A large number of fish (or other sea creatures) of the same species swimming together.
   c. 1661, Edmund Waller, On St. James's Park Beneath, a shoal of silver fishes glides.
   He came directly from the shoal which we had just before entered, and in which we had struck three of his companions, as if fired with revenge for their sufferings. 1851, Herman Melville, Moby Dick

verb

1. To collect in a shoal; to throng.
   The fish shoaled about the place.