The word cuckold is a centuries-old metaphor for a deceived husband and is taken from the habits of the European cuckoo bird.
In the spring, the cuckoo bird lays a single egg in the nest of some other bird to be hatched and then fed among its own chicks by the unsuspecting host.
When a husband has been cuckolded, his nest has been violated by another, who might well have left behind his own offspring.
