Wikipedia
Shootfighting is a combat sport and martial art, with competitions governed by the International Shootfighting Association (ISFA). Shootfighting incorporates techniques from a multitude of traditional martial arts, the most principal of these being Muay Thai and catch wrestling.
Shootfighting was previously used synonymously with mixed martial arts competitions in Japan, as opposed to shoot-style professional wrestling competitions. This usage of the term is retired from common usage because it became a registered trademark of Bart Vale, who uses it to describe his hybrid fighting system derived from shoot wrestling. However, it is still sometimes used colloquially.
Examples which were once considered shootfighting styles, tournaments or organizations are Pancrase, shoot boxing and Shooto, where many fighters still considered themselves to be shootfighters. Ken Shamrock is possibly the most recognisable shoot fighter, as this was the discipline he was credited as using in the early days of the UFC.