Keyword stuffing refers to an outdated search engine optimisation practice where a website is stuffed with an unnatural amount of keywords or key phrases in order to rank higher in search engine results. This practice is often considered spamming and is heavily devalued or even penalised by search engines such as Google and Bing.

Keyword stuffing can be done in various ways, such as adding keywords to invisible text areas such as meta tags or repeating keywords in an unnatural way within the text of a website. The intention is to manipulate search engines in order to achieve a higher ranking in the search results.

However, keyword stuffing can have a negative impact on the user experience, as website content can appear unreadable or irrelevant if too many keywords are used. Instead, website content should be created organically and naturally to improve the user experience while maintaining the website's relevance to search engines.