expression
glowing dark red
Archaic poetic expression describing a deep, glowing red, often associated with the madder plant (茜) and used as a pillow word (枕詞) in classical poetry.
「茜さす」は、古い和歌で夕日や朝日を修飾する枕詞として使われた。
"Akane sasu" was used as a pillow word in old waka poetry to modify words like sunset or sunrise.