So where's your tupence in the mail for the heirs and assigns of Noah Webster you spelling thief! Stop your illegal and immoral derivative use of his work immediately!
Words cannot be copyrighted. Facts cannot be copyrighted. That heirs can reap the rewards of copyrighted works is another issue, that Congress has warped copyright from its original intent.
Copyright ends a certain length of time after the death of the author. Noah Webster is wayyyy over that line.