Definitions for "Stop Word"
Word or words that search engines ignore when they process a query and index the web page.
Search engines and directories ignore certain "stop words" like single letter, two-letter and three-letter words (a, the, of, and, but). These common words do not contribute to relevancy and are not recognized in a query.
Certain words, such as "the," "a", "an," "of," and "with," are so common and meaningless that a search engine won't bother including them in their index, or database, of web page content. So in effect, the stop words on your web pages are ignored as if those words weren't on your pages in the first place. Including a lot of stop words in your title tag waters down the title tag's keyword density. [ edit