George Lucas got the word Jedi from Jidaigeki, which is a Japanese term for Samurai period Drama

Star Wars creator George Lucas has admitted to being inspired significantly by the period works of Akira Kurosawa, and many thematic elements found in Star Wars bear the influence of Chanbara filmmaking. In an interview, Lucas has specifically cited the fact that he became acquainted with the term jidaigeki while in Japan, and it is widely assumed that he took inspiration for the term Jedi from this.[1][2][3]