1. people who make smart remarks or act like they know everything
Usage: informal; plural of wiseguy
2. members of organized crime groups, especially the Mafia
Usage: slang; plural of wiseguy

Examples

• The teacher got tired of the wiseguys in the back row making jokes during class.
• Those wiseguys think they know better than everyone else.
• The movie featured several wiseguys from different crime families.
• He hung around with wiseguys from the neighborhood.
• Stop being such wiseguys and listen to the instructions.
• The FBI was investigating connections between local wiseguys and the casino.
• Nobody likes wiseguys who constantly interrupt with sarcastic comments.