tag cloud

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A word cloud, especially one in which the words are metatags, such as keywords, associated with a given computer file or website.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun Internet A visual depiction of user-generated tags, typically used to describe the content of web sites and having the more significant tags shown in correspondingly larger text or a bolder font