adverb
generally; in general; on the whole
Used to make a broad statement about a situation or group, often implying that the statement holds true in most cases. Similar to 一般に, but 一体に can sound slightly more literary or formal.
See also: 一体
この地域は一体に雨が多い。
This region generally gets a lot of rain.
一体に、若者は新しい技術に早く慣れる。
In general, young people quickly get used to new technology.
From 一体 (one body, whole) + adverbial particle に. The sense of 'generally' developed from the idea of considering something as a unified whole.