E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
A cuckold. The cuckoo occupies the nest and eats the eggs of other birds; and Dr. Johnson says it was usual to alarm a husband at the approach of an adulterer by calling out Cuckoo, which by mistake was applied in time to the person warned. Green calls the cuckoo the cuckolds quirister (Quip for an Upstart Courtier, 1620). This is an instance of how words get in time perverted from their original meaning. The Romans used to call an adulterer a cuckoo, as Te cu ulum uxor ex lustris rapit (Plautus: Asinaria, v. 3), and the allusion was simple and correct; but Dr. Johnsons explanation will hardly satisfy anyone for the modern perversion of the word.