Bootin' up Share definition Flag Booting, or Booting up - To inject, or "shoot up" drugs i.e. heroin. A slang term that is a variant of "shooting up" I got kicked out of the coffee shop for "bootin' up" in the bathroom. Bootin' up by DubDoctor April 9, 2015 0 0 Get merch Get the Bootin' up mug. Buy Now — $32.95 See more merch