Jump To:

• 9/11
  9/11

  September 11, 2001: the day on which Islamic terrorists, believed to be part of the Al-Qaeda network, hijacked four commercial airplanes and crashed two of them into the World Trade Center in New York City and a third one into the Pentagon in Virginia: the fourth plane crashed into a field in rural Pennsylvania.
• 9-11
  9-11

  See September 11 attacks.

9/11

American  

[nahyn-i-lev-uhn] / ˈnaɪn ɪˈlɛv ən /

Or 9-11

1. September 11, 2001: the day on which Islamic terrorists, believed to be part of the Al-Qaeda network, hijacked four commercial airplanes and crashed two of them into the World Trade Center in New York City and a third one into the Pentagon in Virginia: the fourth plane crashed into a field in rural Pennsylvania.

---

9-11 Cultural  

1. See September 11 attacks.

---

Etymology

Origin of 9/11

First recorded in 2000–05

Example Sentences

See Examples For:

9/11 9-11

The sentiments of celebrities regarding the attacks of 9/11 will be of interest to many.

From The Wall Street Journal ● Aug. 20, 2026

She also allegedly stated that "she went from a little girl waving an American flag after 9/11 to now having stickers of the falling towers".

From BBC ● Aug. 20, 2026

Cobbled together in the aftermath of 9/11, the agency has 7,100 armed, highly trained agents and another 800 criminal analysts, as well as access to troves of confidential data about hundreds of millions of Americans.

From Salon ● Aug. 15, 2026

Joseph Fransen, the study’s chief author, told the Commission that he took inspiration from the federal government’s 9/11 after-action report, which dissected mistakes leading up to the terrorist attack.

From Los Angeles Times ● Aug. 12, 2026

He’d assign us reports where we reimagined periods of significant deaths—the plague, the world wars, 9/11, et cetera—and how people would’ve behaved had Death-Cast been around to deliver the warning.

From "They Both Die at the End" by Adam Silvera

Based on that timeline, Rice will miss the Chiefs’ voluntary team workouts May 26-28 and June 1-3 and mandatory minicamp June 9-11.

From Los Angeles Times ● May 20, 2026

Unions called the February 9-11 strike, accusing the authorities of ignoring warnings about the safety of infrastructure and failing to invest enough in the network.

From Barron's ● Feb. 9, 2026

Esan is due to be sentenced at Maidstone Crown Court from 9-11 February.

From BBC ● Jan. 8, 2026

The Valley Leadership Academy in Bacup will roll out the remote lessons from September for top set students in years 9-11.

From BBC ● Jul. 16, 2025

With regard to the time of the composition of this discourse, it appears, from chap. x. 9-11, that Samaria was already conquered.

From Christology of the Old Testament: And a Commentary on the Messianic Predictions. Vol. 2 by Ernst Wilhelm Hengstenberg