Yugen

-In Noh Theatre, yugen represents aesthetic feminine beauty.-
"The meaning of "yúgen" can be explored by looking at the
meaning of the chinese characters used to write the word.
Yú means hazy, dim, dark, deep, quiet, otherwordly,
and is found on such words as yúshi (deep contemplation),
yúhei (confinement), and yúkon (spirits of the dead).
Gen means subtle, profound, or dark and it is also a name
for the other world. It is seen in the in words genó
(inmeasurable depth), genshu (subtle beauty), and gensi
(profound mystery or esoteric truth).
Yúgen, the combination of these two characters expresses
profoundity and evanescence detached from reality and indicates
a mystical state in which beauty is but a premise, something of an
unknowable nature."

* Kunio Komparu