The term "Lightsaber" when said or heard is easily identifiable in the Star Wars franchise mainly because that's basically where it came from.
Star Wars as the public is fully aware off belongs to George Lucas, that is now a subsidiary of Disney. Lucasfilm has filed a lawsuit against the founder of "The Lightsaber Academy" Michael Brown and also New York Jedi, the Lightsaber Academy and Thrills and Skills.
George Lucas, Star Wars franchise owner according to The Hollywood Reporter is currently in California federal court further adding to the lawsuit file the act of cybersquatting, trademark infringement and unfair competition. Lucasfilm Brand according to the source was said to be represented by Laura Lin and Kelly Klaus at Munger, Tolles & Olson.
For those who are unaware of what The Lightsaber Academy is, it's pretty self-explanatory. It's an academy founded by Michael Brown that teaches the art of lightsaber dueling, The Light Saber Academy website allows customers to get in touch with the nearest lightsaber instructor for classes. The business also offer teaching certifications, customizable lightsaber components (different hilts and blades) and other merchandise such as shirts and patches.
The "Star Wars" franchise owner states that "there was never licensed or authorized Defendants to make any commercial use of the Lucasfilm Trademarks or any other of Lucasfilm's intellectual properties." The filed complaint also states other issues such as, "Defendants regularly use the Lucasfilm Trademarks without authorization in connection with their businesses", "Defendants use a logo that is nearly identical, and confusingly similar, to Lucasfilm's trademark Jedi Order logo ... round in shape, with six wing-like shapes curving upward (three per side), and an eight-pointed star featuring elongated top and bottom points stretched into a vertical line."
Lucasfilm is now demanding a permanent stop to the business (pertaining to The Lightsaber Academy), actual damages and proceeds, reaching up to $2 million in statutory damages for each trademark infringement. There have been no comments or statements from Michael Brown so far. Documents have been already presented.