A Google bomb is an orchestrated linking campaign that is aimed at creating a high search result for a Web page. Specific keywords are chosen to make a statement – political, humorous or otherwise – about the Web page that is displayed. When these keywords are entered as a search query, the targeted Web page becomes the top result.
Techopedia explains Google Bomb
In one of the more famous Google bombs, then-president George W. Bush’s official White House bio page was linked by pages all around the Web using the anchor text “miserable failure.” Consequently, entering “miserable failure” into Google returned the president’s bio page as the top result. Other famous Google bombs include the Church of Scientology’s official site as the top result for “dangerous cult” and Tony Blair’s online bio as the top result for “liar.” In 2007, Google announced that it had made changes to reduce the effectiveness of Google bombing.