backdoor man An illicit lover; a person with whom one is having an affair. Such a one presumably enters by the back door to avoid being seen.

bedswerver An adulteress; a woman who strays from the marriage bed. Shakespeare used the term in The Winter’s Tale:

cuckold This term for the unwitting husband of an unfaithful wife supposedly derives from the cuckoo bird’s habit of depositing its eggs in other birds’ nests. The theory would have more plausibility if the word were cuckoo itself and were applied not to the injured party but to the adulteress, as is the case in several other languages. According to Dr. Johnson, the cry of “cuckoo” was formerly used to inform the husband, who subsequently came to be dubbed by the term himself. But even this does not account for the transformation from cuckoo to cuckold. A possibly more plausible explanation may be that the suffix-wold, akin to wild, was coupled with coke ‘cock’ to create a compound meaning ‘horn-mad,’ which may well describe a frustrated husband’s condition, in the circumstances. Compare wittol.

false as Cressida Unfaithful, perfidious; pledging love and fidelity while practicing cuckoldry and adultery; two-faced, hypocritical; traitorous. According to legend set during the Trojan War, Cressida, the daughter of a Trojan priest, had exchanged a pledge of everlasting love and fidelity with Troilus, her beloved. When Cressida was offered to the Greeks in exchange for a group of prisoners, the pledge of fidelity was renewed and sealed with an exchange of gifts. But Cressida had barely arrived in the Greek camp when she succumbed to the charms of Diomedes. To make her abandonment of Troilus even more bitter, she wanted Diomedes to wear Troilus’ gift of a sleeve during their frequent encounters. The legend has been immortalized by Chaucer in Troilus and Criseyde and by Shakespeare:

hanky-panky See MISCHIEF.

wear the bull’s feather To be cuckolded. The bull’s feather was a symbol of cuckoldry. A 17th-century song entitled “The Bull’s Feather” popularized this expression.

wear the horns To be made a cuckold, to have an unfaithful wife. The association of horns with cuckoldry appears in many European languages, but no totally satisfactory explanation of the link has been offered. The most plausible relates the cuckold’s “horns” to the spurs of a castrated rooster, formerly implanted at the roots of the excised comb where they reputedly grew into appendages resembling horns. The fact that the German word for cuckold formerly meant ‘capon’ lends considerable credence to this otherwise questionable account. Since the deceived husband has been symbolically stripped of his manhood, the association is logical as well. Whatever the connection, the usage was pervasive. The following appeared in Hickscorner, a pre-Shakespearean drama.

wittol A husband who knows of—and tolerates—his wife’s infidelity. The word is modeled on the older cuckold, with wit-‘knowledge’ as a prefix. Both cuckold and wittol trace back to Middle English; the latter—at least the word—is archaic. Compare cuckold.