昨夜
ゆうべ · yuube · JLPT N5 · noun
night
🌙 昨夜 = yesterday (昨) + night (夜), read yuube from 夕べ, evening
The kanji spell the meaning: 昨 as in 昨日 (yesterday) plus 夜 (night). The reading yuube is a native word, 夕 (yuu, evening) + べ (around), borrowed onto these kanji. The same spelling can also be read sakuya, the more formal version.
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.