Nobody is sure of the exact meaning, but it applies to an ancient sword so that ought to give you an idea.
"He took his vorpal sword in hand:"
...
"The vorpal blade went snicker-snack!"
(Lewis Carroll, Jabberwocky)
...
"The vorpal blade went snicker-snack!"
(Lewis Carroll, Jabberwocky)
by Pyoko November 26, 2002