jack

/dʒæk/
noun
  1. A device used for lifting heavy objects, especially a vehicle, off the ground.
    • The mechanic placed the jack under the frame of the truck.
    • Always make sure the jack is on solid, level ground before lifting.
    • He used a car jack to lift the tire off the ground.
  2. A playing card with a picture of a young man, ranking between the 10 and the queen.
    • He placed the jack of spades on top of the pile.
    • In many card games, the jack is worth 10 points.
    • She drew a jack and a king in her poker hand.
  3. A connector used to plug in audio or electronic equipment, such as a headphone jack.
    • Make sure the jack is fully inserted into the port.
    • He plugged the cable into the audio jack on the speaker.
    • The headphone jack on my phone is broken.
  4. A small, six-pointed metal object used in the game of jacks, or the game itself.
    • She tossed the jack into the air and tried to pick up the others.
    • The children played jacks on the sidewalk during recess.
    • He won the game of jacks by catching all the pieces.
  5. A male donkey.
    • A jack is often used to guard livestock because of its loud bray.
    • The farmer bred his jack with a female horse to produce a mule.
    • The jack stood in the field, braying at the sunrise.
  6. A flag flown on a ship, especially a small one at the bow, indicating nationality.
    • The ship flew the Union Jack at its bow.
    • The captain ordered the jack to be raised as they entered port.
    • A naval jack is often a smaller version of the national flag.
verb
  1. To lift or raise something using a jack.
    • They jacked the heavy crate onto the platform.
    • She jacked the sofa to slide the rug underneath.
    • He jacked up the car to change the tire.
  2. To increase or raise something, especially a price or amount, often suddenly or unfairly.
    • The store jacked up the price of milk during the storm.
    • They jacked the rent by 20 percent without warning.
    • The company jacked up fees for late payments.
  3. To steal or take something, often by force or without permission.
    • He got his phone jacked at the concert.
    • Someone jacked his bike from the front yard.
    • They tried to jack the car at gunpoint.
  4. To quit or abandon something, often used with 'in' or 'up'.
    • He decided to jack in his job and travel the world.
    • I'm going to jack it in and start fresh.
    • She jacked up the project after the funding fell through.
Antonyms
adjective
  1. Tired of or bored with something; fed up (usually used in the phrase 'jack of').
    • She's jack of doing all the work by herself.
    • I'm jack of hearing the same excuses every day.
    • He's jack of the constant delays.