The Lamanites converted by the four sons of Mosiah and their missionary companions took upon themselves the name of "Anti-Nephi-Lehies." (Alma 23:17; Alma 24:1-5.) The "Nephi-Lehi" part of the title probably had reference to the lands of Nephi and Lehi (or the people then living in those lands) rather than to the descendants of Nephi or Lehi.
However, Dr. Hugh Nibley has found "a Semitic and common Indo-European root corresponding to anti that means 'in the face of' or 'facing,' as of one facing a mirror, and by extension either 'one who opposes' or 'one who imitates.' " (Quoted in Eldin Ricks, Book of Mormon Study Guide, p. 63.) Thus the term "Anti-Nephi-Lehies" might refer to those who imitate the teachings of the descendants of Nephi and Lehi.