夜更け
よふけ · yofuke · JLPT N1 · noun
night
🌙 夜 (night) + 更け (deepening) = night growing deeper into its late hours
更ける means to advance or deepen, as a season or the night does. 夜更け is the hour when the night has grown deep, well past evening.
夜 — 亠 lid + 亻 person + 夕 evening moon
夜 originally depicted a person (亻) under a roof (亠) with the moon (夕) beside them, evoking nighttime rest. The moon component 夕 carries the meaning of evening, while the surrounding elements set the scene of a person at night. Over time it came to mean 'night' in general.
更 — 丙 (bǐng) phonetic + 攴/攵 (action/strike)
Originally an oracle-bone graph showing a hand striking a watch-drum to mark night watches, hence 'to change shifts.' From this came the meanings 'to change' and 'to replace' (gēng). The reading gèng later developed the sense 'further, even more,' as in 'one watch further on.'