noun

• A man.
  "After Dinner they frisk away to some known Place of Rendezvous, where (at Night) every Jack has his Jill and every Jill has her Jack."
• A man.
  "Call you me daughter? now I promiſe you / You haue ſhewd a tender fatherly regard, / To wiſh me wed to one halfe Lunaticke, / A mad-cap ruffian, and a ſwearing Iacke, / That thinkes with oathes to face the matter out."
• A man.
• A man.
  "When Wardell arrived on the scene, they were surprised to find that he was unshaven, and did not look too happy. One of them remarked: "The 'Jacks' (detectives) are after you.""

verb

• (transitive) To physically raise using a jack.
  "He jacked the car so that he could replace the brake pads."
• (transitive) To raise or increase.
  "If you want to jack your stats you just write off failures as invalid results."
• (transitive, colloquial) To steal (something), typically an automobile; to rob (someone).
  "Someone jacked my car last night!"
• (intransitive) To dance by moving the torso forward and backward in a rippling motion.

adj

• (Australia) Tired, disillusioned; fed up (with).
  "In the end, black and white were both crawling on the ground in reconciliation. Both saying that they were plain jack of each other."

noun

• (slang, baseball) A home run.
  "The year before ('76) Kingman had 37 jacks with only 502 PAs. Is that the limit?"