9/11

noun /naɪn.əˈlɛvn̩,naɪn.wənˈwən/

a) The date of the attack on the Twin Towers and the Pentagon in the USA, 11th September, 2001.

Eleven million Spaniards responded to "their 9/11" by demonstrating in the rain against terrorism and their governments policies.

b) The attack itself.

Moussaoui says he wants more 9/11s