jokerPronunciation: /ˈdʒəʊkə/Translate joker | into French | into German | into Italian | into Spanish Definition of joker noun 1a person who is fond of joking. informal a foolish or inept person:a bunch of jokers 2a playing card, typically bearing the figure of a jester, used in some games as a wild card. 3US a clause unobtrusively inserted in a bill or document and affecting its operation in a way not immediately apparent. Phrases the joker in the pack a person or factor likely to have an unpredictable effect on events: the joker in the pack is, of course, the political situationjoker in other Oxford dictionaries Definition of joker in the US English dictionary