you don't know jack!

• Jack FM, a radio format in the United States
• Jack (name), originally a nickname for John (including list of people with that name)
• Jack (device), a device used to lift heavy objects
• Jack (connector), an electrical connector
  • Jack plug, a common audio connector
• Jack (playing card), the lowest face card in a deck of playing cards
• Jack (mascot), the clown mascot of American restaurant chain Jack In The Box
• Jack (human modeling), a human modeling and simulation system
• Jack (film), a 1996 American film directed by Francis Ford Coppola and starring Robin Williams
• Jack (tree), a relative of the mango
• Jack (Tekken), a series of robots in the Tekken series
• Jacks, playground game for children
• Jacking, a form of dance popular in the late 1980s
• JACK Audio Connection Kit, a computer sound server
• Jack (cat), a cat on Blue Peter.
• Jack plane, a tool for smoothing wood
• Jack Daniel's, a brand of whiskey
• Jackfruit, a species of tree native to the East Indies
• Sailor
• Jacks, maritime flags flown from the bow of a ship
• Jack the Ripper (19th century), alias given to an unidentified serial killer of Victorian England
• Spring Heeled Jack (19th century), a legendary figure of Victorian England
• Jack the Stripper (mid-20th century), nickname given to an unknown serial killer of London, England who stripped victims

See also

• Crackerjack (disambiguation)
• Jack-in-the-Box (disambiguation)
• All pages beginning with Jack
• Jack of all trades