The Geno are the practitioners of the faith known as the Path, a nontheist belief system that focuses on enlightenment and inner peace through moderation. The Geno, in accordance with their faith, are shaved bald and wear clothing made of grey cloth. They do not use their birth names, and instead become known only as Geno.
Interestingly, the etymology of the name Geno is counter to the teachings of the Path. Geno is derived from the Greek eugenes (ευγενής, "born to nobility"), but the teachings of the Path say that all are equal. It is unknown how or why the name Geno came to be used to by the practitioners of the Path.
Who is a Geno?
Although the name Geno is used as a label for those who follow the Path, the Geno believe that all people are Geno, but that some simply have not found their Path.
While there has been some confusion, Geno Garon is, in fact, not a Geno in the sense that he does not follow the Path. He is, in fact, a Lewisite.