1911 Encyclopædia Britannica/Kipper

KIPPER, properly the name by which the male salmon is known at some period of the breeding season. At the approach of this season the male fish develops a sharp cartilaginous beak, known as the “kip,” from which the name “kipper” is said to be derived. The earliest uses of the word (in Old English cypera and Middle English kypre) seem to include salmon of both sexes, and there is no certainty as to the etymology. Skeat derives it from the Old English kippian, “to spawn.” The term has been applied by various writers to salmon both during and after milting; early quotations leave the precise meaning of the word obscure, but generally refer to the unwholesomeness of the fish as food during the whole breeding season. It has been usually accepted, without much direct evidence, that from the practice of rendering the breeding (i.e. “kipper”) salmon fit for food by splitting, salting and smoke-drying them, the term “kipper” is also used of other fish, particularly herrings cured in the same way. The “bloater” as distinct from the “kipper” is a herring cured whole without being split open.