ずいぶん昔

a long time ago

→ 随分
phrase Rare #34,008
a long time ago ずいぶん intensifies 昔, meaning a very long time ago.
JA: ずいぶん昔にここへ来たことがある。
EN: I came here a long time ago.

ずいぶん昔の話よね?

That was a long time ago, wasn't it?

— オッペンハイマー (2023)

ずいぶん昔にあの歌を歌ったの、覚えてるよ。

I remember singing that song a long time ago.

もうずいぶん昔のことよく遊びに行ってたわ

That was a long time ago. I used to visit a lot.

— When Marnie Was There (2014)

スペンサーポートに船の女主人がいたのは、ずいぶん昔のことだ。

It was a long time ago that the lady of the ship lived in Spencer Port.

ずいぶん昔だ

That was a long time ago.

— 灼熱の魂 (2010)