I don't know why someone would tell you that Star Wars
was an homage to The Seven Samurai
. Their stories are very different. SS is about a village being terrorized by bandits and recruiting a motley group of defenders who teach them how to defend themselves.
As for the definition of "Western," it's true that nominally it refers to a story taking place in the American West during the frontier era, but I think that's taking it too literally. After all, the version of the American West seen in movies and TV never really existed; it's a mythology created by the makers of motion pictures. So in a way that makes it timeless, a set of storytelling symbols and tropes that don't literally correspond to a specific place or time and thus can be mapped onto other settings.