Definition of jack up in English:

jack up

informal
  • 1Inject oneself with an illegal drug.
    More example sentences
    • 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?
  • 2Australian Give up or refuse to participate in something.
    More example sentences
    • 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.
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Word of the day coloratura
Pronunciation: ˌkɒlərəˈtjʊərə
noun
elaborate ornamentation of a vocal melody