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last night; yesterday evening
「昨夕」 has another reading with different meanings.
昨夕はよく眠れたかい?
Did you sleep well last night?
昨夕の雨はすごかったね。
The rain last night was intense.
昨夕食べたレストランの料理がおいしかった。
The food at the restaurant I ate at last night was delicious.