Definitions for "Keyword density"
This is the concentration percentage (compared to the overall word count) of the keyword or keyword phrase on a web page. Each search engine algorithm has its own "optimum" keyword density. The density can be obtained from the page body text, meta tags, alt tags, links and headings.
The proportion of relevant words and phrases on a Web page; used by search engines as a criterion for determining a listing's ranking.
the ratio or the number of times your keywords appear in your web page in relation to the total number of words appearing in that same web page. If your keywords appear 7 times in a web page with 100 words in it, then your keyword density would be 7 divided by 100, then multiplied by 100 to arrive at the percentage of 7%.
Keywords:  context, relative, site, web, amount
The relative amount of keywords present within the context of a Web site.