definition of
joker

[1] #1 joker n. [jokester] a person who enjoys telling or playing jokes. wn

[2] #2 joker n. [turkey] a person who does something thoughtless or annoying; "some joker is blocking the driveway". wn

[3] #3 joker n. 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". wn

[4] #4 joker n. a playing card that is usually printed with a picture of a jester. wn