A name attached to a thing from outside it. A label describes; it does not constitute, and it can be wrong about what it names.
Old French label/lambel (a ribbon, a strip of cloth, a heraldic mark), of Germanic origin, related to lap (a flap, a fold); a name attached to a thing from outside it, as a ribbon is fastened rather than born with it.
A name fastened onto a thing from outside it, able to describe wrongly precisely because it was never part of what it names.