Nonmelodious is a term that describes something that lacks a pleasant or harmonious sound. Synonyms for nonmelodious can include discordant, dissonant, harsh, jarring, raucous, grating, or cacophonous. Discordant implies a lack of agreement between musical notes or tones, resulting in a jarring or unpleasant sound. Dissonant suggests a harsh or clashing combination of sounds. Harsh can describe a sound that is rough, unpleasant, or painful to listen to. Jarring refers to something that produces a sudden or unpleasant shock to the senses. Raucous and grating are similar in meaning, describing something that produces a harsh, grating, or rough sound. Cacophonous suggests a confused and discordant mixture of sounds.