Gothabilly comes from a blending of Gothic and Rockabilly. The earliest use of the word Gothabilly was by The Cramps in the late 70s who used it to describe their own blend of somber, Rockabilly influenced punk. Since then the term has come to describe a fashion trend in the Gothic subculture.
This is the interbreeding of Goth’s black silks, satins, lace and velvet with Country-Western elements like cowboy hats and boots, handkerchiefs, western shirts and bolo ties. Through in some elements from the retro culture revival, including stylized flames, 50s tattoo imagery and street-rods of every sort and you see where the aesthetic is heading. The current use of Gothabilly include both it’s fashion and music implications.
Many of today's Gothabilly bands seem to be from California. However it is by no means exclusive to that state. There are bands popping up all over the US and from many other countries. In fact one of the more notable English Goth bands (Fields of the Nephilim) had some serious Western influences and can be classified as Gothabilly.
The Brimstones, Graveyard Farmers, Jake the Evil Redneck, and Mr. Underhill are examples of gothabilly bands.