Also, on the bum or fritz . Malfunctioning, out of order, broken, as in The TV is on the blink again, or You drive-our car's on the bum. The first of these slangy expressions dates from the late 1800s and possibly alludes to an electric light that flickers on and off ("blinks"); the second, from the same period, possibly is derived from bum in the sense of "a contemptible person"; the third, fritz, dating from about 1900, is of unknown origin.