柯林斯词典diurnal /daɪˈɜːnəl/ 1. ADJ Diurnal means happening or active during the daytime. 白日的[正式] [usu ADJ n] Kangaroos are diurnal animals. 袋鼠是昼出动物。 返回 diurnal剑桥词典happening over a period of a day , or being active or happening during the day rather than at night 在一天内发生的；白天发生的；昼行性的 比较nocturnal 返回 diurnal