cuckold

Concise Oxford English Dictionary © 2008 Oxford University Press:
cuckold /ˈkʌk(ə)ld/

▶noun the husband of an adulteress regarded as an object of derision. ▶verb make (a married man) a cuckold.

– derivatives
cuckoldry noun.

– origin OE, from OFr. cucuault, from cucu ‘cuckoo’ (from the cuckoo's habit of laying its egg in another bird's nest).