I Love Words
Here are Mirriam-Webster's top ten words, based on the number of lookups on their website.
1. democracy
2. quagmire
3. quarantine
4. matrix
5. marriage
6. slog
7. gubernatorial
8. plagiarism
9. outage
10. batten
For definitions, go to http://www.merriam-webster.com/info/03words.htm