The Book of Mormon refers five times to the Israelite prophet Zenock, spelled Zenoch in the Original manuscript of the Book of Mormon (1 Nephi 19:10, Alma 33:15, 34:7, Helaman 8:20, and 3 Nephi 10:16.
According to research by Diane Wirth, John Robertson, and Brian Stubbs, the name Zenock, from the Book of Mormon, and Tenoch, the Nahuatl name of a semi-legendary priest/leader of the Aztecs, may be linguistically related. Tenoch is believed to be one of the founders of Tenochtitlan, the Aztec city that was thriving at the time of the Spanish Conquest. The Nahuatl name Tenoch may originally have been Tenoch or Zenoch. Tz, z, t, and ts combinations are used in Mesoamerican languages, sometimes with one taking place of the other, depending on the region where it was used. In the case of the name Zenoch, the shift to Tz, followed later by dropping the Z, would give us Tenoch.
The migration of the Nephites from the land southward, which was probably in an area that eventually became predominantly Maya-speaking, to the land northward (Helaman 3), where Nahuatl dialects were probably spoken, might help account for a spelling change such as the shift from Zenoch to Tenoch. Tenochtitlan today underlies a portion of Mexico City. This is in the same general area as remnants of Nephite civilization, at least according to the most likely theories. [Diane E. Wirth, John S. Robertson, and Brian Stubbs, "Did Book of Mormon Names Persist in Ancient America?", F.A.R.M.S. Update, Number 87, March 1993]