経けい年ねん変へん化か

noun, noun or participle which takes 'suru'

change over time; aging; secular change

Refers to gradual change in properties or appearance due to the passage of years, often used for materials, products, or natural phenomena. Can be used as a noun or with する to describe the process.

• この素そ材ざいは経けい年ねん変へん化かで色いろが濃こくなる。

  This material darkens in color over the years.

• 建たて物ものの経けい年ねん変へん化かを調ちょう査さする。

  We investigate the aging of the building.