To spread out or extend (in area, range, influence, etc.); to reach or fill a space. Used in many contexts: physical expansion, spread of news/infection, an expression spreading across a face, etc.
朝靄が町全体に広がって景色がぼんやり見える。
Morning mist spread over the whole town, making the scenery look hazy.
彼の冗談に笑いが広がった。
Laughter spread in response to his joke.
新しいウイルスが短期間で全国に広がった。
The new virus spread nationwide in a short time.
テーブルクロスを広げてピクニックの準備をした。
We spread out a tablecloth and prepared for the picnic.