Superior, first-class, excellent; of high quality or grade.
これは上等なワインだから大切に保管しよう。
This is a fine wine, so let's store it carefully.
上等な布地を使ったスーツは着心地が違う。
A suit made from high-quality fabric feels different to wear.
彼の仕事ぶりは上等だと評価された。
His work was judged to be excellent.
Interjection meaning 'that's fine!' or 'bring it on!' used to accept or challenge with a tough/energetic nuance.
『手伝ってくれないの？』『上等だ！任せろ』
'Won't you help?' 'Fine! Leave it to me.'
そんなことを言うなら、やってみろ、上等だ。
If you're saying that, then try it—bring it on.
給料を上げろと言われても、対応できないなら『上等』とは言えない。
Even if they demand a raise, you can't say 'fine' if you can't meet it.