A kipper is a whole fish that has been split from tail to head, eviscerated, salted, and smoked. Typically, the species is a herring or salmon, but traditionally it is any fish found in great numbers and caught during its spawning period. Spawning fish are not good to eat fresh and usually arrive in great abundance, thus they are salted and smoked to improve flavor and preservation.
The exact origin of kippers is unknown, though fish have been slit, gutted and smoked since time immemorial. According to Mark Kurlansky, "Smoked foods almost always carry with them legends about their having been created by accident - usually the peasant hung the food too close to the fire, and then, imagine his surprise the next morning when..."Mark Kurlansky, 2002. Salt: A World History, ISBN 0802713734. One example of this legendary origin can be found in the story of John Woodger at Seahouses in Northumberland, England around 1843, in which kippering happened accidentally, when fish for processing was left overnight in a room with a smoking stove. We know this to be false because the origin of the word kipper is Old English; the English philologist and ethnographer Walter William Skeat derives it from the Old English kippian, to spawn. We know smoking and salting of fish—in particular of spawning salmon and herring which can only be made edible by this practice—predates 19th Century Britain and indeed written history, probably going back as long as man has been using salt to preserve food. We also know kippered fish were eaten in Germany and reached Scandinavia sometime during the Middle Ages.
As a verb, to kipper means to preserve by rubbing with salt or other spices before drying in the open air or in smoke. So beef or other meat preserved in the same fashion can logically be called "kippered."
The Manx word for kipper is skeddan jiarg which literally translates as red herring.
Kippers today are extemely popular in the Isle of Man where thousands are produced annually in the City of Peel where two kipper houses smoke herring and export them to the world: Moore's Kipper Yard and Devereau & Son Ltd. A kipper meal is known as tatties and herrin in the Scottish Lowlands and spuds and herrin in the Isle of Man, where kippers are usually served with potatoes and buttered bread.
The catchphrase of Red Dwarf character Ace Rimmer is "Smoke me a kipper, I'll be back for breakfast."