A discordant sound is an unpleasant noise that is made up of a combination of different sounds that do not go together. CACOPHONY is a nine-letter word that describes this type of sound, and it is often used to describe a loud, harsh, and dissonant sound. JANGLE is another six-letter word that can be used to describe discordant sound, and it is typically used to describe a sound that is made up of many different notes that are played or sung at the same time.