"Someone whose job is to collect taxes for the government. The term is often used to refer to the tax authorities." (CD)
The graph displays the other subjects mentioned on the same pages as the subject "Tax collectors". If the same subject occurs on a page with "Tax collectors" more than once, it appears closer to "Tax collectors" on the graph, and is colored in a darker shade. The closer a subject is to the center, the more "related" the subjects are.