Source:Ricks:Tvedtnes:The Hebrew Origin of Some Book of Mormon Place Names:JBMS 6:2:The name Jershon means "to inherit"

The name "Jershon" in the Book of Mormon

The Hebrew root of the name "Jershon" means "to inherit" and denotes a place name

When the Lamanites converted by the sons of Mosiah fled their homeland to escape persecution, the Nephites allowed them to settle in the land of Jershon. The name, though not found in the Bible, has an authentic Hebrew origin, the root *YRŠ,13 meaning "to inherit," with the suffix -ôn that denotes place-names.14 Wilhelm Borée, in his outstanding study, Die alten Ortsnamen Palästinas (The Ancient Place Names of Palestine), cites fully 84 ancient Canaanite place names with the ending - ôn in biblical and extrabiblical sources (Egyptian and Mesopotamian writings, the El-Amarna letters, ostraca), including Ayyalon (Elon) (Joshua 19:42, 43), Eltekon (Joshua 15:58), Ashkelon (Judges 1:18), Gibeon (Joshua 9:3), Gibbethon (Joshua 19:44), Dishon (Genesis 36:21), Ziphron (Numbers 34:9), Helbon (Ezekiel 27:18), Holon (Joshua 21:15), Hammon (Joshua 19:28), Hebron (Joshua 10:36), Hannathon (Joshua 19:14), Dibon (Numbers 21:30), and Heshbon (Numbers 21:30).15
It is in this light that we should understand the words in Alma 27:22 ("and this land Jershon is the land which we will give unto our brethren for an inheritance"), Alma 27:24 ("that they may inherit the land Jershon"), and Alma 35:14 ("they have lands for their inheritance in the land of Jershon").