プログレッシブ和英中辞典(第4版)の解説
よいのくち【宵の口】
((in)) the early evening
彼にとっては12時は宵の口だ
To him 12 midnight is still the beginning of the evening.
泥棒が入ったのは宵の口だった
It was early in the evening when the burglar broke in.
まだ宵の口だ
The night is still young./《米口》 It's just the shank of the evening.