Keyword stuffing is the excessive use of the main keyword or related but unnecessary keywords that have little or nothing to do with the actual content of the page.
Little piggy stuffing itself with keywords
Keyword stuffing involves using the keyword as frequently as uruguay cell phone number list possible in the text (preferably in undeclined form) and on the page. With this practice, the focus is again on the search engine, not the user. This goes against the grain of Google, whose mission is to always provide the user with the best answers. Texts that suffer from keyword stuffing and are clearly written for search engines certainly do not fall into this category.
Search engines' understanding of language has now advanced to the point where they can deduce what your text is about based on context and synonyms. The relevance of keywords in a text is therefore decreasing; the use of keywords is becoming increasingly rare on your page.