noun, noun which may take the genitive case particle 'no'
unparalleled beauty; matchless beauty throughout the land
Literary and somewhat archaic set phrase describing a woman of supreme beauty, often in classical or poetic contexts.
彼女は国色無双と称えられた。
She was praised as a woman of unparalleled beauty.
国色無双の姫君が都に現れたという噂が広まった。
Rumors spread that a princess of matchless beauty had appeared in the capital.
A four-character compound from classical Chinese, combining 国色 (national beauty) and 無双 (unparalleled). The exact historical derivation is uncertain, but it is used in Japanese as a set literary phrase.