Joker/ˈdʒəʊkər/ Definition 1 of 5Pro Tip 1/2Social Interaction Used when someone is being humorous in casual conversation or social gatherings. At the party, Mike was the joker, telling funny stories. Pro Tip 2/2Positive Feelings Indicates a person who brings joy and laughter, usually appreciated in friendly settings. Sarah is such a joker, she always cheers me up.