Definition of jack up in US English:

jack up

phrasal verb

  • 1Inject oneself with an illegal drug.

    • ‘In the brief moment which followed Lincoln's veins swelled up with a delicious nectar as if she were a hard up junkie just jacked up with a long sought after injection of her favorite narcotic.’
    • ‘Eric was just tired and still a little jacked up on drugs, then they did some therapy and he got even more tired.’
    • ‘He was still pretty much jacked up on drugs, and the rest of the team had practically left.’
    • ‘And how else are you going stop a 350 pound guy, all jacked up on drugs?’
    • ‘The song gives you the feeling of being a race car driver jacked up on amphetamines.’
  • 2Australian Give up or refuse to participate in something.

    • ‘And it's the same with ADHD, there's a continuum of this behaviour and it gets to a point where either the parents, the teachers jack up or doctors say here's the behaviour beyond which we would say this is a disease.’