Thus, it seems the term "tariff" was first applied to designate the "rates," or duties which the Roman Catholic priests levied upon sins.
Via Simon Lester, more here. It comes from the Arabic d'araf, meaning "to know".
As for 'austerity', this article gives the run-down on Merriam-Webster's 2010 Word of the Year, and includes some quotes from IPE prof (at Brown) Mark Blyth (who is researching a book on the topic). We covered Blyth, and a video preview of his book, previously.