四し六ろく時じ中ちゅうしろくじちゅうJLPTN1›Freq.FrequencyTop 50,000Meanings1adverb, nounaround the clock; day and nightyojijukugo (four-character idiom)›Emphasizes continuous, all-day-and-night activity. Derived from 4×6=24, representing the 24 hours of the day.