sexual liaison; amorous encounter
A literary yojijukugo derived from a Chinese legend about a king's dream encounter with a goddess on Mount Wu. Used in classical or poetic contexts to refer to a romantic or sexual meeting.
The story of the amorous encounter on Mount Wu originates from classical Chinese literature.
From the Chinese legend of King Huai of Chu, who dreamed of a goddess on Mount Wu (巫山) and shared clouds and rain (雲雨) with her, a classical euphemism for sexual union.