shad
n.n. a type of fish that is similar to a salmon. It is known for swimming upstream to lay its eggs.
n. any of several species of fish of the genus Alosa, belonging to the herring family. Characterised by an anadromous life cycle, where adults migrate from the ocean to freshwater to spawn.
The local fishermen caught a large shad in the river.
During the spring migration, the shad can be seen swimming upstream in large schools to reach their spawning grounds.
While the shad is often overshadowed by its more famous cousin, the salmon, it plays a vital role in the aquatic ecosystem by providing a significant food source for larger predators.
From Middle English shadde, from Old English sceadd, possibly from Celtic (compare Scottish Gaelic sgadan (“herring”), Welsh ysgadan) or from Scandinavian/North Germanic (compare dialectal Norwegian skadd (“small whitefish”), Old Norse skata (“kind of fish”)), but the order of borrowing is unclear and the ultimate origin of these words is obscure.