Zoramites is a term used over the course of the entire Book of Mormon to refer to a subgroup of the Nephites. The name originates from Zoram, who was the servant of Laban. Zoram followed (or was compelled to follow) Lehi and his family to the promise land (the Americas). When the Lamanites splintered, Zoram and his family stayed with the Nephites. The name continues over the generations. Ammoron, who took control of the Lamanites, used his lineage from Zoram as justification for leading the Lamanites against the Nephites. The name persists in the records as a clear subgroup of the Nephites up until the destruction of the Nephites. 
The group should not be confused with the Zoramites in Alma, who rebelled against the word of God.