OK, I think the size 14 Define is an error because I can't actually order one. Hmm, I thought Luluemon was going to have a new and improved website after the New Year. There is some interesting commentary by Road Wariorette about Lululemon's website in this Yoga Dork post about Athleta opening a store in San Francisco.
One thing I am puzzled about is that the No Limit on the website only goes up to a 10. My local stores only had it to a 10 also. Several people have written they have bought this tank in a 12 so I am not getting the disconnect. If you regularly take a size 12 and can't find a size 12 No Limit, I think the Aruba is a bit stretchier than the other colors so you might want to try that one.