A vehicle lacking proper air conditioner function. Typically, a jalopy, or otherwise embarrassingly mal-conditioned vehicle. The result of riding in said vehicle is the dreaded sweatback, or sweaty back syndrome.
Bill drinks a gallon of gatorade and takes off his shirt before driving home in his sweatback.
A person who displays an overall lack of motivation. These individuals typically avoid responsiblity and situations that require work. Pronounced "Slay-ker"