Became softer, calmer, or more mature in attitude; developed a richer or smoother quality over time.
From Middle English 'melow,' possibly related to 'mellow' meaning soft or ripe. The word describes the process of softening—whether fruit ripening or a person becoming kinder with age.
Wine and cheese get better as they mellow, but so do people—neuroscience shows that our brains literally become less reactive as we age, which is why older people seem wiser (they might just be chemically calmer).
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