A person who starts doing drugs and joins a group of people who are heavily into that drug(s) already. Then after a short while, leaves the group because they can't keep up with the group's high level of partying.
a device mounted in tandem with either a turbocharger or supercharger. its purpose is to cool the air charge coming in from the turbo/supercharger. cooler air is denser, so it packs more power.
an intercooler is your turbocharger's best friend.