9/11

1 4.4

Terrorist attacks on September 11 2001 in the US when hijacked planes hit the World Trade Center and Pentagon

noun

: atentados del 11 de septiembre

Examples

He was taken out because he was an obvious potential sponsor of future 9/11s.

Blog text (10)
The catastrophic events of September 11, 2001, are commonly referred to as 9/11.
Many people around the world remember where they were when the 9/11 attacks occurred.
The impact of 9/11 can still be felt in global security policies today.

Synonyms

Sept. 11

vs9/11

18 4.4

A day in 2001 when terrorists attacked New York and Washington

is the event described as plane hijackings striking specific targets

September 11 attacks

vs9/11

5 3.4

Terrorist attacks in the United States on September 11, 2001 using hijacked planes

is the widely used label for those specific strikes on that date

September 11

vs9/11

3 3.8

A day in 2001 when terrorists attacked the United States, destroying the World Trade Center and damaging the Pentagon

is used to mean the attacks themselves rather than only the date

9-11

vs9/11

1 3.5

Terrorist attacks on September 11, 2001 in the United States when hijacked planes hit important buildings

is the same event name but written in a numeric punctuation form

event of 9/11

vs9/11

1 4.6

Terrorist attacks in the United States on September 11, 2001 that killed many people and changed world politics

focuses on the factual strike details without mentioning broader effects

Sep 11

vs9/11

4.4

The day when terrorists used hijacked planes to attack the United States in 2001

emphasizes the attacks and their method rather than merely the calendar date

Compounds

event of 9/11

1 4.6

Terrorist attacks in the United States on September 11, 2001 that killed many people and changed world politics

Surface Forms

9/11 singular

9/11s plural

Etymology

9/11 Comes from the United States way of writing dates as 'month/day', so '9/11' stands for 'September 11, 2001'. Because of the terrorist attacks on that day, the numbers 9/11 became a short, memorable name for those events, so today 9/11 refers to the attacks and their anniversary.