Redouble means quadruple, or double?

"Redouble" means "quadruple" rather than "double with an oomph"?

Does it?

It ought to, but so many people use it to mean double with an oomph that this may be what it does mean. If it does mean quadruple, then you would need to do it one more time (the thing, not the quadrupling), making five, if you wanted to pip the redoublers to the post. "Redouble and then some" is what I'd do.

From http://www.newenglishreview.org/blog_direct_link.cfm?blog_id=4587