sep 11 sep • sepad · · · Info · Definitions · Characters · · sep 11 · · Text Common · · Latin · · Scripts 6 · · Length 4 · · Syllables Definitions · · · (noun) the day in 2001 when Arab suicide bombers hijacked United States airliners and used them as bombs. Synonyms: 9/11, 9-11, September 11, Sept. 11, Sep 11. · · Noun Definition 1 Characters · · space U+0020 1 digit one U+0031 e latin small letter e U+0065 p latin small letter p U+0070 s latin small letter s U+0073