noun, noun which may take the genitive case particle 'no'
middle age; midlife
Refers to the period of life roughly between 40 and 60 years old. Can be used as a noun or as a no-adjective to describe things related to middle age.
彼は中年になってから健康に気をつけるようになった。
He started paying attention to his health after reaching middle age.
中年
A middle-aged man is jogging in the park.