壮そう年ねん期き

noun

prime of life; heyday

Refers to the period when a person is at their physical and mental peak, typically middle age. Often used in literary or formal contexts.

• 彼かれは壮そう年ねん期きに大おおきな成せい功こうを収おさめた。

  He achieved great success in the prime of his life.

noun

stage of maturity

Geological term for a mature stage in landscape development, such as a river valley or landform. Technical use.

• この地ち形けいは壮そう年ねん期きの特とく徴ちょうを示しめしている。

  This landform shows characteristics of the stage of maturity.