ab off

slang To rappel down from a mountain-climbing route. "Ab" is a shortening of "abseil," a largely British term meaning "rappel." Primarily heard in UK. The climb itself is very challenging and fun, but there's nothing to do once you reach the top, so I usually just ab off straight away when I finish the climb. I don't like the look of those storm clouds. We'd better start abbing off. A: "I've been recovering from an injury, so I haven't been mountain climbing in quite a while." B: "We can ab off at any point if it gets to be too much."