なんだい

what?

→ だ

phrase Rare #37,696

what? An informal, often masculine-sounding way to ask a question. It can sound blunt or old-fashioned.

JA: なんだい、急に呼び出して。

EN: What is it? Why did you call me all of a sudden?

それが何なんだい？

What is that?

— ロード・オブ・ザ・リング／王の帰還 (2003)

いつまで文句を言うつもりなんだい？

How long are you going to keep complaining?

いくつなんだい？

How old are you?

— 紅夢 (1991)

一体全体どこへ行くつもりなんだい。

Where on earth do you think you're going?

ねえ兄さんなんだい

Hey, bro. What is it?

— 東京物語 (1953)