Tisha b'Av literally means - the 9th of Av- and it's a day of fasting and mourning for the Jewish people. They mourn the destruction of the Beit HaMikdash (Temple) in Yerushalayim and all the destruction that came upon the Jewish people ever since. It's a very sad day, probably the saddest day in Jewish history, a day when the Jews beg for the reconstruction of the third Temple and the coming of Mashaich. May it be HaShem's will that the Beit HaMikdash will be rebuilt soon and the redemption of the Jewish people begins. Bo Yeshua! Come Yeshua!
Bat Melech בת מלך