To leave a particular area on foot, esp. at a high rate of speed (e.g. running). This is usually done in anticipation of an unfavorable confrontation or undesirable characteristics of the area.
Most often used in the context of escaping from a particular situation. Named because of the motion and sound produced during the process, i.e. beating one's feet against the pavement.
My bitter ex-girlfriend showed up at the party I was at, so Jeff gave me a heads up and I beat feet.
There were a lot of graffiti and gang members on High Street, so Fred and I beat feet.