Refers to a person who practices or is skilled in martial arts (武術). Often implies a dedicated practitioner rather than a casual student.
He is a famous martial artist who trained many disciples.
Drawing on his experience as a martial artist, he worked as an action director for films.
格闘家 is a broader term for a combat sports athlete or fighter, including modern MMA and boxing, whereas 武術家 is more traditional.
Compound of 武術 (bujutsu, 'martial arts') + 家 (ka, 'practitioner, expert'). The term is straightforward and modern, with no obscure historical derivation.