First there was hillbilly, and then there was rockabilly. Originally referring to a style of music, rockabilly has since become a style of clothing inspired by the fashions of the 1950s and '60s, particularly in the US.
It's a great look for anyone who enjoys stylish, comfortable, retro fashion. This was the style of the sock hop, and it's still popular with many people. Put the music on, kick off your shoes and dance in rockabilly fashion.