literally, iron-throat; perhaps this was a necklace made of metal or a metal throat band that was put on slaves?; Molina says it was the same as the tepuzquauhcuzcatl (metal-wooden-necklace?)
a copper finisher Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 10 -- The People, No. 14, Part 11, eds. and transl. Arthur J. O. Anderson and Charles E. Dibble (Santa Fe and Salt Lake City: School of American Research and the University of Utah, 1961), 26.