Creating a Drupal 7 module to implement dictionary functionality

This is the first time I have been working with Drupal but I think I understand the basics now. There is one thing that I would need to write my own module for in order to implement: a dictionary. How would I best go about creating such a module?

These are my preliminary thoughts on the steps needed to accomplish this: First I would need to create a node/block that allows users to enter a word they would like to have translated. Then that string has to be grabbed and broken down into the grammatical components. Lastly I need to query the database and return the results. Ordinarily this would not be that difficult if I were just dealing with regular PHP but I have to make this work within Drupal and I do not know what functions or hooks to use and I am not familiar enough with Drupal to know how to best approach this.

Any help or suggestions would be greatly appreciated!

umm, why not use taxonomy? You can use that with views 3+ and it's pretty much all point and click to make a "glossary view" or the taxonomy terms. taxonomy is also fieldable so you could even add things like file attachments for audio pronunciation guides, or pronunciation key, or whatever.

.. an exposed filter can also provide term lookup..

Would that be possible? You see the translation is from Latin to German. I have to be able to determine the grammatical form of any variation of any word that is entered and trace it back to the basic form in order to give a translation.

hmm, so you have two options I guess. store all of the words in their various grammatical forms with a reference to a taxonomy term that is the root term, and then provide the definition there on the taxonomy term.

Or attempt to programmatically match the declension and grammatical form in order to strip away the use-case specific component for a genric lookup. 

Depends on how many "exceptions to the rule" there are -- probably mostly in the first declension but maybe more than I remember.