that mr2 is running only 9pounds of boost stock but with the help of a electric/manuel boost controller he can push up to 15pounds of boost without changing any engine internals.
A term most often overly used by ricers and so called "import tuners". Usually used to define how much a car's air intake is pressurized, measured in PSI or bar.
"Dude, I'm running 18 lbs of boost in my beatercivic with a 100 shot of Nawssss."