Which word describes a harsh, discordant sound?

The term that describes a harsh, discordant sound is "cacophony." This word is commonly used to refer to a mixture of sounds that are jarring and unpleasant to hear. It evokes an image of noise that lacks harmony and instead presents a clash of different tones, resulting in a chaotic auditory experience.

In contrast, the other options represent concepts associated with pleasing sounds. "Harmony" refers to the combination of different musical notes played or sung simultaneously to produce a pleasing effect. "Melody" describes a sequence of notes that are tuneful and recognizable, often forming a memorable tune. "Symphony" pertains to a complex musical composition typically involving an orchestra, which is characterized by its harmonious and structured nature. This distinction makes "cacophony" the clear choice for describing a harsh, discordant sound.