Slang term used to describe a URL that is not easy to read from a human perspective. For example, a messy URL might look something like this: http://www.webopedia.com/article.php/3831706/
In contrast, a clean URL would contain more meaningful words, like this:
A messy URL is not only harder for human readers to decipher, but it can often make it difficult for search engines to use the data in the URL for indexing purposes. Most messy URLs are the result of dynamically generated URLs that are created using publishing and content management systems.