I had a look at the code for the dictionary block. PHPMyAdmin refused to install the file (even after zipping it) perhaps because it was too big. I'm afraid this large database will really slow down the display of the block especially since the block doesn't cache the output: for every pagevisit the block counts the number of words in the database (why? there is no way to add word to the list, so the number could as wel be calculated once and then stored) and then selects a random one.
- Google lists some nice rssfeeds which display a word of the day. You could use the newsfeed block to display one each day. (The newsfeed block caches so it will not slow down the display of the course page)
- If you want to have the search functionality without importing the complete dictionary, you can copy code inside your block to produce a form which links to an external dictionary when students enter a word. (Look at the Google search block or the Wikipedia block)
- If you really want to use the Gutenberg Project dictionary, I think I may have a solution to import it in the glossary module. Then you can use the glossary search function and it is easier to (make students) add own words to the glossary. You can use the glossary random block to display a new word every day / every pagevisit / always the last added word / etc...