"ABnormal END" - Abnormal termination (of software); {crash}; {lossage}. Derives from an error message on the IBM 360; used jokingly by hackers but seriously mainly by {code grinder}
s. Usually capitalized, but
may appear as `abend'. Hackers will try to persuade you that ABEND is called `abend' because it is what system operators do to the machine late on Friday when they want to call it a
day, and hence is from the
German `Abend' = `Evening'.