noun
Poetic and dated term for the first light of dawn. Often used in classical literature and poetry; in modern Japanese, 夜明け or 明け方 are more common.
東雲の空が美しい。
The sky at daybreak is beautiful.
彼は東雲の頃に起きて散歩に
He got up around dawn and went for a walk.
The reading しののめ is a jukujikun (special kanji reading) assigned to the kanji 東雲, which literally mean 'east cloud'. The exact origin of the reading is uncertain, but it is traditionally associated with the faint light appearing in the eastern sky before sunrise.