young-old
n.— «Another meaningful division of the life cycle is now appearing in the rise of the young-old, a group drawn mainly from the 55-to-75 age group. The young-old are distinguished from the middle-aged primarily by retirement, and distinguished from the old-old by continued vigor and active social involvement.» —“The Rise of the Young-Old” by Bernice L. Neugarten New York Times Jan. 18, 1975. (source: Double-Tongued Dictionary)
Further reading
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