协和

As a proper noun, 协和 is the Chinese name of Peking Union Medical College (北京协和医学院) and its hospital 北京协和医院 - founded 1917 by the Rockefeller Foundation and still one of the most prestigious hospitals in China. The word 协和 ("to harmonize") was picked as a calque of "Union". Also the Chinese name of the Concorde supersonic jet (协和式飞机).

In everyday speech most commonly encountered as part of institutional names (协和医院, 协和学院). The bare adjective 协和 (harmonious) is formal/literary - colloquially you'd use 和谐.