Meaning of 9/11 in English

9/11

n. September 11th, the September 11 attacks, September 11, 2001, day in the year 2001 on which a destructive attack of terrorism was launched against the United States by Islamic terrorists when two hijacked commercial planes deliberately crashed into the Twin Towers and destroyed them (approximately 3,000 people lost their lives) and another plane deliberately crashed into the Pentagon (189 people who worked at the Pentagon were killed)

Explanatory English dictionary bed edition.      Толковый словарь английского языка Редакция bed.