Meaning

noun flesh of shad-like fish abundant along the Atlantic coast or in coastal streams

noun shad-like food fish that runs rivers to spawn; often salted or smoked; sometimes placed in genus Pomolobus

originUnknown. Possibly from aloof, the Narragansett name of a fish. See Winthrop on the culture of maize in America, “Phil Trans.” No. 142, p. 1065, and Baddam’s “Memoirs,” vol. ii. p. 131. Possibly from allowes (“a type of shad”), from French alose (“shad”), from Old French [Term?], from Late Latin alausa, influenced by Etymology 1 due to large belly of the fish.

Etymology from Wiktionary, CC BY-SA 3.0