A cuckold is the husband of an adulterous wife. In evolutionary biology, the term is also applied to males who are unwittingly investing parental effort in offspring that are not genetically their own.
The word cuckold derives from the cuckoo bird, alluding to its habit of laying its eggs in other birds' nests. The association is common in medieval folklore, literature, and iconography.
English usage first appears about 1250 in the satirical and polemical poem "The Owl and the Nightingale" (l. 1544). The term was clearly regarded as embarrassingly direct, as evident in John Lydgate's "Fall of Princes" (c. 1440). In the late 14th century, the term also appeared in Geoffrey Chaucer's "The Miller's Tale". Shakespeare's poetry often referred to cuckolds, with several of his characters suspecting they had become one.
One often-overlooked subtlety of the word is that it implies that the husband is deceived, that he is unaware of his wife's unfaithfulness and may not know until the arrival or growth of a child plainly not his (as with cuckoo birds).
The female equivalent cuckquean first appears in English literature in 1562, adding a female suffix to the cuck.
A related word, first appearing in 1520, is wittol, which substitutes wit (in the sense of knowing) for the first part of the word, referring to a man aware of and reconciled to his wife's infidelity.
In Western traditions, cuckolds have sometimes been described as "wearing the horns of a cuckold" or just "wearing the horns." This is an allusion to the mating habits of stags, who forfeit their mates when they are defeated by another male. In Italy (especially in Southern Italy, where it is a major personal offence), the insult is often accompanied by the sign of the horns. In French, the term is porter des cornes, which is used by Molière to describe someone whose consort has been unfaithful. In German, the term is "jemandem Hörner aufsetzen", or "Hörner tragen", the husband is "der gehörnte Ehemann". Rabelais wrote the Tiers Livers of Gargantua and Pantagruel in 1546, by which time the symbol of the horns was "so well-known and over-used that the author could barely avoid making reference to it."Molière's L'École des femmes (1662) is the story of a man who mocks cuckolds and becomes one at the end. In Geoffrey Chaucer's Canterbury Tales (c. 1372–77), the "The Miller's Tale" is a story that humorously examines the life of a cuckold. In Chinese usage, an altogether different allusion is used, when the cuckold (or wittol) is said to be "戴綠帽子" (wearing the green hat), which derives from the sumptuary laws used in China from the 13th to the 18th centuries which required the males in households with prostitutes to wrap their heads in a green scarf (or later a hat).