Obsolete term for shade; replaced by 日陰 (ひかげ) in modern Japanese.
See also: 日陰
In old documents, 日裏 is seen as a word meaning shade.
Compound of 日 (hi, 'sun') and 裏 (ura, 'back, reverse side'), literally 'the back side of the sun', i.e., shade. The exact historical derivation is uncertain.