adverb
what on earth; why in the world; who or where the heck
Placed before an interrogative word such as 何, 誰, どこ, なぜ, or どう to make a question emphatic. It often expresses surprise, confusion, suspicion, or irritation, but is not inherently vulgar.
一体何があったんですか。
What on earth happened?
彼は一体どこへ行ったのだろう。
Where in the world did he go?
noun
one whole; single unit or group; single form or style
Noun use for things functioning as one body, unit, group, mass, form, style, or format. Common in patterns such as 一体となる, 一体にする, and 一体のデザイン.
チームが一体となって最後まで戦った。
The team fought as one until the end.
全体を一体のデザインにまとめた。
We brought the whole thing together in a unified design.
noun
one statue or sculpture; one corpse; one remains sample
Only when written 一体 / １体
Numeral-counter use with 体, especially for Buddhist images, statues, figures, corpses, and samples of bones or remains. The Arabic-numeral spelling １体 is mainly useful in such counting contexts.
本堂には仏像が一体安置されている。
One Buddhist statue is enshrined in the main hall.
現場から遺体が一体見つかった。
One body was found at the scene.
adverb
generally; on the whole; for the most part
Adverbial use, often as 一体に. It is somewhat written or formal compared with more everyday expressions such as 一般に or だいたい.
See also: 一体に
この地方の冬は一体に雨が多い。
In general, winters in this region have a lot of rain.
adverb
strictly speaking; in the first place; originally
Dated adverbial use. In modern Japanese, そもそも, 本来, or 厳密に言えば is usually used instead, so this sense is most likely to appear in older or explanatory contexts.
古い文章では、一体を「そもそも」「本来」という意味で読むことがある。
In old writing, 一体 may be read with the meaning 'to begin with' or 'originally.'