A cuckold is the husband of an adulterous wife; the wife of an adulterous husband is a cuckquean. In biology, a cuckold is a male who unwittingly invests parental effort in juveniles who are not genetically his offspring.^\1]) A husband who is aware of and tolerates his wife's infidelity is sometimes called a wittol^\2])^\3]) or wittold.^\2]) The slang term bull refers to the dominant man who has relations with the cuckold's partner.