Windsor knot definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
a form of double slipknot in a four-in-hand necktie, resulting in a wider, bulkier knot
Windsor knot definition by American Heritage Dictionary
A wide, triangular slipknot used to tie a four-in-hand necktie.
Origin: Perhaps after the Duke of Windsor.