Noise is a collection of signals with random amplitudes and frequencies within specific parameters over time. Excellent!
Noise is the lack of musical context. Noise can mean different things to different people, but for this unit, noise has a specific meaning.
Noise is an unpleasant signal that the majority of the public voted to be unpleasant. Noise can mean different things to different people, but for this unit, noise has a specific meaning.
Noise is a collection of generators with random inputs that do not change at all over time. The change over time part is what makes the sound 'noisy'.