Ashura

According to majority of lexicologists the words “‘Ashur", “‘Ashura” and “‘Ashura’” is the name of the 10th of Muharram. Some added that, etymologically, ‘Ashura’ is a Hebrew word which is changed to ‘Ashur in Arabic. In Hebrew it is the name of the 10th of Tishri (the first month in the Jewish calendar)

Source : wikishia