A state of the economy resulting from an extended period of negative economic activity as measured by GDP. It is often described as a more severe form of a recession that leads to extended unemployment, a spike in credit defaults, broad declines in income and production, currency devaluation and a deflationary economy.
I know that the Great Depression was the longest and most severe depression ever experienced by the industrialized Western world, sparking fundamental changes in economic institutions, macroeconomic policy, and economic theory.
Wilson's 14 points were far more radical than the outcome of the Paris Peace Conference. The 14 points set specific barriers to prevent a future war and maintain peace, while the Paris Conference only offered temporary mediation.