slang Of or characterized by an earlier era or older style. Can either refer to that which is considered antiquated or old-fashioned, or else to that which is remembered fondly or nostalgically. Sometimes hyphenated. My dad likes to play music on this old-school record player. I don't know why he doesn't just get an iPod. Whoa, a vintage Ford Mustang. That's so old school, man! Her parents are pretty old school when it comes to living together before marriage.