- a person who is brashly and annoyingly conceited, knowing, etc.; smart aleckalso written wise guy
- a hoodlum or gangster; esp., a member of the Mafia
- An example of a wiseguy is an arrogant person at work who is always making sarcastic comments that he thinks are hysterical.
- An example of a wiseguy is a man in the Mafia who has been made one of the crime bosses.
The definition of a wiseguy is a smart-aleck who is annoying and full-of-himself, or a member of the Mafia or other organized crime syndicate.