Origins
The word 'egg' holds a special place in the history of English because it is the subject of one of the most famous anecdotes in early English linguistics.βββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββ In 1490, the printer William Caxton β the man who introduced the printing press to England β described in the prologue to his translation of the Aeneid a merchant who, traveling from the north of England to Kent, stopped at a house along the Thames and asked for 'egges.' The woman of the house replied that she did not speak French. Another traveler intervened and asked for 'eyren,' the southern English form, and was understood immediately. Caxton used this story to illustrate the difficulty of writing for an English-speaking audience whose language varied so dramatically from region to region.
The linguistic situation Caxton described was the result of Viking settlement. Old Norse 'egg' and Old English 'Η£g' both descended from the same Proto-Germanic ancestor *ajjΔ , which itself came from PIE *hβΕwyΓ³m (egg). The two words were cognates β not a borrowing replacing a foreign word, but a Scandinavian form replacing its own English twin. The difference in pronunciation arose from centuries of independent development: Old English *ajjΔ evolved through i-mutation and other changes to 'Η£g' (and its plural 'Η£gru,' later 'eyren'), while Old Norse preserved a form closer to the Proto-Germanic original.
In the Danelaw β the region of northern and eastern England under Scandinavian legal and cultural influence β the Norse form 'egg' predominated. In the south and west, the native form 'ey' (with plural 'eyren') held firm. For centuries, these two forms coexisted in a geographical split that roughly followed the old political boundary between English and Danish territory. The eventual victory of the northern Norse form was driven partly by London's growing absorption of northern vocabulary and partly by the influence of print standardization in the late fifteenth century.
Proto-Indo-European Roots
The PIE root *hβΕwyΓ³m produced cognates across the Indo-European family. Latin 'ovum' (egg), the source of English 'oval,' 'ovary,' 'ovulate,' and 'ovoid,' descends from the same root. Greek 'Εion' (egg) is another cognate, as is Old Church Slavonic 'ajΡce.' The Proto-Germanic form *ajjΔ regularized the root with the characteristic Germanic nominal ending, producing the ancestor of both the English and Norse words.
The phrase 'to egg on,' meaning to incite or urge, is unrelated to the noun 'egg.' It comes from a different Old Norse word, 'eggja,' meaning 'to incite' or 'to edge on,' from 'egg' meaning 'edge' (the same root that produced English 'edge'). This is a coincidence of modern English spelling, not a genuine semantic connection.
The word 'egg' in its modern form perfectly illustrates the depth of Norse influence on English. This was not a case of English borrowing a word for a new concept; Anglo-Saxons obviously already had eggs and a word for them. The Norse word replaced the native word in the most intimate domain of daily vocabulary β food β which suggests a level of Scandinavian cultural prestige and social integration that went far beyond mere military conquest. When a language changes its word for something as basic as an egg, the speakers of the incoming language are not distant overlords but neighbors, spouses, and trading partners.