- shoal (1)
- "place of shallow water," c.1300, from O.E. schealde (adj.), from sceald "shallow," from P.Gmc. *skala- (cf. Swed. skäll "thin;" Low Ger. schol, Fris. skol "not deep"). The terminal -d was dropped 16c.
- shoal (2)
- "large number" (especially of fish), 1579, apparently identical with O.E. scolu "band, troop, school of fish," but perhaps rather a 16c. adoption of cognate M.Du. schole, both from P.Gmc. *skulo- (cf. O.S. scola "multitude," W.Fris. skoal), perhaps with a lit. sense of "division," from PIE base *skel- "to divide." Related to school "a crowd of fish" (q.v.). For possible sense development, cf. section from L. secare "to cut."