Spamdexing, coined from spam and index, is the practice of including information in a Web page that causes search engines to index it in some way that produces results that satisfy the spamdexer but usually dissatisify the search engine providers and users. When the extraneous information appears in a page's meta tags, it is called "overstuffing".
Some examples of spamdexing and overstuffing:
Including a key word dozens or even hundreds of times on a Web page so that a search engine will weigh the relevance of this page to the subject word more heavily than pages on other Web sites. The subject words are usually placed at the very end of the page out of the reader's way or can even be made invisible to the reader (but readable by the search indexing program).
Including one or more subject words that are totally unrelated to the subject of the Web site for the purpose of getting people to visit the site. In a typical example, the word "sеx" might be listed as a key word (or spamdexed at the bottom of the page) on a site that really sells books on "highly effective sales techniques."
Punishing someone by including their name as a key word on a site with which they have no connection or even a contentious connection.
Trying to capture a competitor's traffic by listing their name or trademarks in the meta tags (this is often a violation of copyright law).