noun which may take the genitive case particle 'no', noun
past middle age; nearing old age; near-elderly
Refers to the stage of life when one begins to feel the approach of old age, typically around the 40s to early 60s. Often used in formal or written contexts.
彼は初老の男性だが、とても元気だ。
He is a man past middle age, but he is very energetic.
初老の夫婦が公園を散歩していた。
An elderly couple nearing old age was taking a walk in the park.
noun
age 40 (original meaning)
Historically, 初老 referred specifically to the age of 40. This usage is now rare and mainly found in classical or explanatory contexts.
古くは、初老は40歳を指す言葉だった。
In the past, 初老 was a term that referred to the age of 40.