Definition

1. Proper noun:
   • A specific date referring to the terrorist attacks in the United States on September 11, 2001: The term denotes the day when hijacked commercial airliners were used as weapons in coordinated attacks, primarily targeting the World Trade Center in New York City and the Pentagon near Washington, D.C.

Usage

• The term "September 11" is used as a singular event marker, often to refer to the attacks themselves and their immediate aftermath. It is commonly abbreviated as 9/11.
• It functions as a temporal reference point in historical, political, and social discussions.

Examples

• As a proper noun (event):
  • The security policies of many countries were fundamentally reshaped after September 11.
  • Memorials are held every year on September 11.

Advanced Usage

• "Post-September 11 world": Used to describe the global geopolitical and social climate following the 2001 attacks.
  • Aviation security changed dramatically in the post-September 11 world.
• "September 11 attacks" / "9/11 attacks": A more descriptive compound phrase specifying the nature of the event.
  • The September 11 attacks were a series of four coordinated terrorist attacks.

Variants and Related Words

• 9/11: The standard numerical abbreviation for September 11, overwhelmingly used to refer to the 2001 attacks.
  • The 9/11 Memorial and Museum is located in New York City.
• 9/11 Commission: The common name for the National Commission on Terrorist Attacks Upon the United States.
• Post-9/11: An adjective describing the period or conditions after the attacks.

Synonyms

• 9/11: (The primary synonym, used interchangeably).
• The September 11th attacks: (A more formal descriptive synonym).

Notes on Meaning

• While "September 11" literally refers to the eleventh day of the ninth month, in contemporary English usage, when capitalized and used without further qualification, it almost exclusively refers to the terrorist attacks of 2001. The context usually makes this meaning clear.
• It is distinct from the simple calendar date, which would typically be written in a different context (e.g., ).

Noun

1. the day in 2001 when Arab suicide bombers hijacked United States airliners and used them as bombs