Daily newsletters can really catch on if you find the right audience. Just look at "Cool Site of the Day." One that could get traction is an email newsletter highlighting slang words that are growing in popularity. Teens especially would keep an eye on it for new words they've never heard of that are on the cutting edge. If you get creative, build a brand around it, and grow a fan base on Facebook/Twitter it could take off. Some of the words might go viral as a result of the ezine.
There are lots of newsletter services online that you can use to send it. The title of it is the hard part with so many names already taken. Some potential catchy names with domain names that have not yet been registered (at the time of this post) and which look to have no trademark on them (be sure to double check if you go with one of these) are:
"Mind" could be a good word to work off of since readers would be learning about new words for their vocabulary. Have fun with it if you decide to give it a shot!