in the Roman calendar: the 15th of March or May or July or October or the 13th of any other month
例句
Beware the Ides of March.注意三月十五日。
The ninth day before the ides of a month; in the ancient Roman calendar, the seventh day of March, May, July, or October and the fifth day of the other months.古罗马历中自三、五、七、十各月的十五日起算的前第九日即三、五、七、十各月的第七日; 其它各月的第五日
