Was reading something (English) yesterday and came across two words I\'d never seen before and had to look up. That doesn\'t happen that often, and it occurred that given the number of language enthusiasts and non-native users of English we have on here, this might be an interesting topic. 

My words were: 

Sumptuary. As in sumptuary laws, which govern... no, not sumps. Consumption. I did think maybe I should have used that in recent translations on rules on consumption by government officials in China - what can be served at banquets and so on. Sure enough, the Economist got there first.