To have etymologies (not just definitions) is a very specific requirement for a thesaurus. Could you please provide more info on this one. Please use comments to explain how you see this to be done Examples would be the best.
In regards to just definitions – they are available by using Definitions list. We are also planning to provide a neat way to access specific definitions on a term level within the lists.shawn commented
I'm on your website, which seems like every day, but i always have a dictionary on my side to figure the best word. this would be very helpful!