Let the hive mind of Engadget get that for you.
"I am looking for a device that will stream sound from one source to several recipients. For example, I want to stream sound from my TV or stereo to my phone or MP3 player that has radio and Bluetooth capabilities. I have looked into radio transmitters and they seem like a decent choice, but I can't find one that uses external power (USB or from the plug) and I would want one with a transmit range of around 50 meters. Thanks!"
Well, not really, it's merely a definition. Same reason you don't classify an orange as an apple, just because it's tasty too ;) As far as the definition, anything else is just HD quality resolution if you must put the HD moniker on there.
Totally off topic, Borat, that is an odd name (to me at least), you don't play WoW do you under that name? Maybe it has some fantasy background I don't know about if not?