I have a web application that serves as a dictionary, and it ranks good at google when searching for a rare word in my language (the dictionary's target language). I want the result to appear in the define: some-word, as well as in the search results when someone uses the filter tool Dictionary.

Should I add some special meta-tag in the head of the html? How about microdata?

Does google have a special webmaster tool for registering dictionaries like: wordnetweb.princeton.edu or en.wiktionary.org ?