The "xxnx" part could refer to various things, such as a website, a tag, or a keyword. One possibility is that it's related to a adult or entertainment website, but without further clarification, it's difficult to say for sure.
The year "2013" suggests that the search is for content from that specific year. 2013 was a significant year for many reasons, including major events in technology, entertainment, and social media. photo xxnx 2013 hot