Here is one of the most useful web-sites I have found, especially since I am having so much trouble speaking and learning Thai.
Of course a better way is to purchase the program and have it on the computer all the time – no Internet needed and much, much faster. But if you only occasionally need to look-up the Thai meaning or translate Thai into English – then the online version will do just fine. Check it out. http://www.thai2english.com/online/