/shad/ , n. , pl. ( esp. collectively ) shad , ( esp. referring to two or more kinds or species ) shads .
1. a deep-bodied herring, Alosa sapidissima, of Europe and North America, that migrates up streams to spawn, used for food.
2. any other fish of the genus Alosa or related genera.
3. any of several unrelated fishes.
[ bef. 1050; OE sceadd (not recorded in ME) ]