shoal \shohl\,
noun:
1. a place where a sea, river, or other body of water is shallow.
2. a sandbank or sand bar in the bed of a body of water, especially one that is exposed above the surface of the water at low tide.
adjective:
1. of little depth, as water; shallow.
verb:
1. to become shallow or more shallow.
2. to cause to become shallow.
3. Nautical. to sail so as to lessen the depth of (the water under a vessel).
A few minutes later Tom was in the shoal water of the bar, wading toward the Illinois shore. Before the depth reached his middle he was half way over; the current would permit no more wading, now, so he struck out confidently to swim the remaining hundred yards.
-- Mark Twain, "The Adventures of Tom Sawyer," 1876
That piece of land is permeated with a perfect shoal of mineral springs.
-- Ada Clare, "Only a Woman's Heart," 1886
Shoal comes from the Old English term sceald meaning "shallow." It was spelled with a d up until the 1500s.
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