mel·low / ˈmelō/ • adj. 1. (esp. of sound, taste, and color) pleasantly smooth or soft; free from harshness: she was hypnotized by the mellow tone of his voice slow cooking gives the dish a sweet, mellow flavor. ∎ archaic (of fruit) ripe, soft, sweet, and juicy: a dish of mellow apples. ∎ (of wine) well-matured and smooth: delicious, mellow, ripe, fruity wines.2. (of a person's character) softened or matured by age or experience: a more mellow personality. ∎ relaxed and good-humored: Jean was feeling mellow. ∎ inf. relaxed and cheerful through being slightly drunk: everybody got very mellow and slept well.3. (of earth) rich and loamy.• v. make or become mellow: [tr.] getting older does mellow the hard edges around the anger | [intr.] fuller-flavored whiskeys mellow with wood maturation | inf. I need to mellow out, I need to calm down. DERIVATIVES: mel·low·ly adv.mel·low·ness n.