The Hebrew root word Jerash (???) meant "to inherit." When they put a nun (?) at the end of a word, as in Jersh-on, it meant "a place of"—it is a toponymical suffix—and so the name Jershon literally means "a place of inheritance, " and it was given to them “for an inheritance” (Alma 27:22).
Book of Mormon Central, “Why Was Jershon Called a Land of Inheritance? (Alma 27:22).” KnoWhy 134 (July 1, 2016).
“Jershon,” Book of Mormon Onomasticon.