Logic (from the Greek logos, which has a variety of meanings including word, thought, idea, argument, account, reason or principle) is the study of reasoning, or the study of the principles and criteria of valid inference and demonstration.
Go to Google Trends (see resources below). Google Trends is a great way to find most popular searched words on Google. It lists the top 100 searched words and is frequently updated throughout the day. You can click on any of the search words and find out more information about it. Go to Yahoo Buzz.
Word Search (beta). This tool is a pattern matching tool for words that you have a few letters for. For now its only going to give you the possible words, but in the future I hope to add things like definitions for each word so you can see if they match what you're trying to find.