adverb
what the heck; why in the world; who on earth
Emphatic form of 一体, used in questions to express strong puzzlement, frustration, or insistence. Often paired with question words like 何, どうして, 誰, etc.
一体全体、何が起こったんだ？
What the heck happened?
一体全体、どうしてこんなことになったんだろう
Why in the world did things turn out like this?