Meaning of Rou-gai(老害)

It means “annoying old person.”
Rou(老) means old, gai(害) means harm.

Several years ago, it means “annoying old person who has authority”. For example, old politician, old officer, old boss… They have old-fashioned values, and we know it’s not correct in the modern society.
But these days, it means “annoying old person”. For example, old neighbor, old customer… Some of old people are stubbornness and selfish.

Japan is facing an aging population, that’s why this word became popular.
Old people have money but young people are poor. Young people feel stuck in this society. They have different values.
We know it’s difficult to continue to grow, but “Rougai” believe it and say “if you feel it difficult it’s because you don’t work hard”. it’s annoying.

Example Conversation

A: Tanaka is a really Rougai.
B: Why? Whant’s happend?
A: He said “Don’t complain such a small volunteer over time work. When I was young, I worked more frantically.”
B: Wow, he is a really Rougai. You worked overtime over 80hours last month!

A: 田中さんってマジで老害だよな。
B: なんで？なんかあったの？
A: 「それくらいのサービス残業で文句言うな。俺が若い時はもっと必死に働いてたぞ」だってさ。
B: うわー。マジ老害だな。先月お前80時間以上サービス残業してたじゃん!