One, Usually a man, who is a loser, but nobody really bother to tell him to get lost. A tool typically wears clothing from Aeropostale, Hollister, Abercrombie, and or American Eagle. A tool usually (but not always) makes 1st grade jokes, is stupid, Has an ear pierced, or is just annoying. A tool is usually used for people to "borrow" money from. The tool sometimes KNOWS he is buying his friends: A loser.
"Micheal is such a tool."
Micheal: "I know why I'm getting F's. I haven't been laid in weeks! I better go to American Eagle"
"I put my iPod in my pocket and it went through the wash. I better go ask best friend Micheal for some money."