a man whose wife committed adultery
"After finding out his wife had been seeing someone else for months, he felt too humiliated to remain in their marriage and left her immediately."
A man married to an unfaithful wife, especially when he is unaware or unaccepting of the fact.
"After finding out his wife had been seeing someone else for months without telling him, he felt devastated to realize he was a complete cuckold in their marriage."
To make a cuckold or cuckquean of someone by being unfaithful, or by seducing their partner or spouse.
"After finding out his wife was having an affair with her coworker, he realized he had become the perfect target for anyone looking to turn a man into a cuckold."