Where does “September eleventh” come from?

September eleventh (English) comes from English eleventh, from Middle English ellevenþe, from Middle English elleven, from Old English endleofan, from Proto-Germanic ainalif, from Proto-Germanic -lif, from Proto-Indo-European leyp-, from Proto-Indo-European lēy- — to leave, let; to want, desire; to let; leave...

September eleventh (English): The terrorist attacks that took place in the United States on September 11, 2001

Definitions

  1. The terrorist attacks that took place in the United States on September 11, 2001

Ancestry of “September eleventh”, step by step

September eleventh traces back through two separate lines of ancestry.

via English eleventh

StepLanguageWordMeaning
1EnglisheleventhThe ordinal form of the number eleven; The person...
2Middle Englishellevenþeeleventh
3Middle Englishelleveneleven
4Old Englishendleofaneleven
5Proto-Germanicainalifeleven
6Proto-Germanic-lifleft over
7Proto-Indo-Europeanleyp-to stick; fat or sticky substance
8Proto-Indo-Europeanlēy-to leave, let; to want, desire; to let; leave...

via English September

StepLanguageWordMeaning
1EnglishSeptemberThe ninth month of the Gregorian calendar, following August and preceding October, containing the southward equinox
2Latinseptemberof September
3LatinSeptemseven; 7
4Proto-Italicseptemseven
5Proto-Indo-Europeanseptḿ̥seven
Every word from Proto-Indo-European lēy-Every word from Proto-Indo-European leyp-Every word from Proto-Germanic -lif