Explanation: An octogenarian is a very old person, 80 or 90 years old. Very old, very old.

Source: [Han] Cao Cao's "Song to Wine": "Anyone who is eighty years old can die, and the grace is as wide as grass and trees."

Extended data sentence:

1, Mr. Guan Ai, as the name implies, people are still worried about the world in their eighties.

2. I am over eighty years old, and nostalgic bosom friends, many fragments between the years he and * * * experienced together, often appear in my mind and reappear.

On Huo's left, there is an old man in marshal's uniform with silver hair and heavy eyebrows.

Eighty years ago, Yuan's prosperous scenery was refreshing. In its eighties, it was spring several times.

Childhood friends, childhood friends, separated by war for decades, continue to lead the way in the octogenarian.