tsòng-liân壯年

prime of life

prime of life; more robust years of a person's life (between thirty and forty or fifty)

English Wiktionary, “壯年” (CC BY-SA 4.0) — https://en.wiktionary.org/wiki/%E5%A3%AF%E5%B9%B4 · confidence: Medium (Wiktionary, Hokkien)