A turbo is defined as a person who in previous high school years was quite, and maybe a hard worker. But since graduating into university has become a loud, alcohol induced, obnoxious freak.
A man or woman who sports the requisite mullet, tight acid washed jeans, hi top sneakers with fat tongues hanging out, a Warrant shirt (or paraphernalia of some such other dirty hair metal band). The turbo loves cars, but due to dire financial straits, can usually not afford a nice one, sometimes opting for a bicycle of equally low caliber.
Larry is such a turbo. I saw him riding home from the beer store with a case of Coors Light on his handlebars. His mullet was flying in the wind and his jeans were so tight I thought he was gonna pass out!