I need a database of every single valid word in English. I checked the /usr/share/dict/words file, it contains less than 100k words. wikipedia says English has 475k words. Where do I get the complete list (American spelling)?
Also, is there a single website that gives out words for other languages too? Including Asian and European?
Edit: Forgot to add, I do not need names etc. Just valid english words.
You can find what you need on infochimps.org.
They have a list of 350,000 simple (ie non-compound) words available for free download.
Word List - 350,000+ Simple English Words
Regarding other languages, you might want to poke around on Wiktionary. Here is a link to all the database backups - the information isnt organized so likely but if they have a language, you can download the data in SQL format.
You didn't say what you needed this list for. If something used as a blacklist for password checks is enough cracklib might be good for you. It contains over 1.5M words.
WordNet database might be helpful. I once worked on a Firefox add-on which deals with words and all kinds of simple to complicated associations between them and stuff. Looks like WordNet will be very much useful to you.
MySQL format - http://androidtech.com/html/wordnet-mysql-20.php
There's no such thing as a "complete" list. Different people have different ways of measuring -- for example, they might include slang, neologisms, multi-word phrases, offensive terms, foreign words, verb conjugations, and so on. Some people have even counted a million words! So you'll have to decide what you want in a word list.
You may check *spell en-GB dictionary used by Mozilla, OpenOffice, plenty of other software.