一体どこ

where on earth

→ 一体
phrase Uncommon #13,323
where on earth An emphatic way to ask where something or someone is, often expressing surprise, frustration, or confusion. 一体 is also commonly written いったい in this use.
JA: 一体どこから来る声なの?
EN: Where on earth is that voice coming from?

一体どこ彼に会ったんだ

Where on earth did you meet him?

一体どこに行ってたんだ

Where on earth have you been?

— 罪人たち (2025)

洋子一体どこへ行ってしまったのだろう

I wonder where on earth Yoko has gone.

一体どこ!

Where on earth?!

— Hoje Eu Quero Voltar Sozinho (2014)

つまりじゃやっぱり課長さん毎日出勤したふりして一体どこ行ってるんですか

So then, where on earth does the section chief go every day, pretending to come to work?

— 生きる (1952)

一体どこ

Where on earth is it?

— イングリッシュ・ペイシェント (1996)

彼女は一体どこに住んでいるのかしら

I wonder where on earth she lives.

カギ一体どこなの

Where on earth is the key?

— REC / レック (2007)