joker joker /ˈdʒoʊkɝ/

noun

1. () A person who enjoys telling or playing jokes  ( jokester , quipster , wisecracker , joker )
   a person who enjoys telling or playing jokes
   
2. A playing card that is usually printed with a picture of a jester  ( joker )
   a playing card that is usually printed with a picture of a jester
    The joker can be used as any card in a game of poker
   The joker can be used as any card in a game of poker
   
   
3. An inconspicuous clause in a document or bill that affects its meaning in a way that is not immediately apparent  ( joker )
   an inconspicuous clause in a document or bill that affects its meaning in a way that is not immediately apparent
    When I demanded my money he showed me the joker in the contract
   when I demanded my money he showed me the joker in the contract
   
4. A person who does something thoughtless or annoying  ( joker , turkey [Informal] )
   a person who does something thoughtless or annoying
    Some joker is blocking the driveway
   some joker is blocking the driveway