1871, invented by Lewis Carroll in "Through the Looking-Glass."
Online Etymology Dictionary, © 2010 Douglas Harper
Examples from the Web for vorpal
And through, and through,The vorpal blade went snicker-snack!
He took his vorpal sword in hand:Long time the manxome foe he sought.The Book of Humorous Verse
He took his vorpal sword in hand;Long time the manxome foe he sought.
Along his line of work he took his “vorpal” sword in hand and severed all the knots and twists of the mathematical Jabberwocky.
Oh, the excitement of that moment when the “vorpal” sword went “snicker-snack” through the writhing neck of the monster!