9/11

 Dictionary entry overview: What does 9/11 mean? 

• 9/11 (noun)
  The noun 9/11 has 1 sense:

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

  Familiarity information: 9/11 used as a noun is very rare.

 Dictionary entry details 

• 9/11 (noun)

Sense 1

Meaning:

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

Classified under:

Nouns denoting time and temporal relations

Synonyms:

9-11; 9/11; Sep 11; Sept. 11; September 11

Instance hypernyms:

terrorist attack (a surprise attack involving the deliberate use of violence against civilians in the hope of attaining political or religious aims)

Domain category:

act of terrorism; terrorism; terrorist act (the calculated use of violence (or the threat of violence) against civilians in order to attain goals that are political or religious or ideological in nature; this is done through intimidation or coercion or instilling fear)

Holonyms ("9/11" is a part of...):

Sep; Sept; September (the month following August and preceding October)