The oohoo pop up dictionary plugin (https://moodle.org/plugins/view.php?plugin=block_dictionary)is a nice plugin, but it could be greatly improved if there were some more default web dictionaries available in the default dropdown menu than the ones currently available. For example, if you were looking for happiness you could use:

http://oxforddictionaries.com/definition/english/happiness?q=happiness
http://www.merriam-webster.com/dictionary/happiness
http://lema.rae.es/drae/?val=felicidad (in spanish)

Or looking for a medical term, such as influenza:
http://vsearch.nlm.nih.gov/vivisimo/cgi-bin/query-meta?v%3Aproject=medlineplus&query=influenza&x=0&y=0

Also, it would be nice to have the wikipedia available in spanish and portugues, as there are many moodle users with those languages.