an alphabetical list of words relating to a specific subject, text, or dialect.

Negative Keyword

This is a search term that you do not want your ads to show for. For example, when you add "compare" as a negative keyword to your campaign or ad group, you tell AdWords not to show your ad for any search containing the term "compare." On the Display Network, your ad is less likely to appear on a site when your negative keywords match the site's content.