dictionary database and webdesign

I need to make make a simple dictionary, english to english, with thesaraus, synynoms ... -We can either build a database, or use a program that catches the information from other sites and puts it in my site... such as in www.thefreedictionary.com. (you have to know the program and how to do this). -After the dictionary is made, I need to work on another simple extension involving the building of a program that will work with the dictionary.