means The quality of lacking any pattern, order, or predictability — when outcomes follow no rule you can pin down.

from From 'random,' which arrived in English via Old French 'randon' meaning a rush, a great speed, or impetuosity — itself tied to 'randir,' to gallop headlong. For centuries 'at random' meant moving with reckless, uncontrolled force, like a horse bolting where it pleased. Only later did that headlong unpredictability cool into the modern sense of 'without pattern.' The abstract noun 'randomness' is a much later, plain English build: 'random' plus the '-ness' that turns any quality into a thing.