In Buddhism, the four basic elements (earth, water, fire, and wind) that make up the universe and the human body.

A political slogan from the People's Republic of China referring to speaking out freely, airing views fully, holding great debates, and writing big-character posters; refers to 大鸣大放 dà​míng​dà​fàng, 大辩论 dà​biàn​lùn, and 大字报 dà​zì​bào

(literary) The four great entities described in the "Dao De Jing": the Way, heaven, earth, and the king.

The four largest companies in a specific industry, most commonly referring to the Big Four accounting firms or major commercial banks