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1.
A month that was once September 1st. Comes from the Latin "sex" meaning six, and is placed in order before (Septem)ber, (Octo)ber, (Novem)ber, and (Decem)ber. September now starts on the 2nd.
Dude, I totally got laid on Sextember.
by Bennett and Luke April 01, 2008