I. cuck ‧ old 1 /ˈkʌk ə ld, ˈkʌkəʊld $ -k ə ld/ BrE AmE noun [countable] old use
[ Date: 1200-1300 ; Origin: Probably from Old French cucuault , from cucu ; ⇨ ↑ cuckoo 1 ]
an insulting word for a man whose wife has been having sex with another man
II. cuckold 2 BrE AmE verb [transitive] old use
if a wife and her ↑ lover cuckold her husband, they have sex with each other