- Japanese: 幽玄 (yuugen)
Yûgen is a concept associated with waka poetry, Buddhism, and most especially Noh theatre. Difficult to translate or define, it refers to an aesthetic of mystery, profundity, and depth, tied in with elements of indescribable beauty, and a metaphorical or conceptual abyss of the unfathomable. It is dark and deep, but in a welcoming, intriguing, and spiritually or intellectually profound way.
- Tom Hare, Zeami Performance Notes, Columbia University (2008), 5.