The suffix hdpart218 breaks down into technical parameters regarding the file's format and location within an archive:
The identifier 1000giri111104sakura hdpart218 describes a specific segment of a high-definition video file. It originates from the "1000giri" label, features a performer named Sakura, was released on November 4, 2011, and represents segment #218 of a split-file archive. 1000giri111104sakura hdpart218