tepozmitl.

Headword: 
tepozmitl.
Principal English Translation: 

iron bolt (Tlatelolco, 1550-80)

James Lockhart, Nahuatl as Written: Lessons in Older Written Nahuatl, with Copious Examples and Texts (Stanford: Stanford University Press and UCLA Latin American Studies, 2001), 194.

Orthographic Variants: 
tepuzmitl
Alonso de Molina: 

tepuzmitl. punzon o alesna.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 104r. col. 1. Thanks to Joe Campbell for providing the transcription.

Attestations from sources in English: 

çan ie no ivi in tepuzmitl in aquin vel quimotilia, aocmo quiça, niman miqui = Likewise when they took good aim at someone with the iron bolts, he did not escape (Mexico City, sixteenth century)
James Lockhart, We People Here: Nahuatl Accounts of the Conquest of Mexico, Repertorium Columbianum v. 1 (Los Angeles: UCLA Center for Medieval and Renaissance Studies, 1993), 188.

tzinacantopilli, in tepuztlavitolli, in tepuzmitl: yoā no vncan maceoaloc in tepuzquacalalatli, in tepuzvipilli, in tepuzmatlavipilli, in eoachimalli, in tepuchimalli, in quauhchimalli=halberds, crossbows, crossbow, bolts. And also they acquired there iron helmets, iron cuirasses, coats of mail, leather shields, metal shields, wooden shields. (Mexico City, sixteenth century)
James Lockhart, We People Here: Nahuatl Accounts of the Conquest of Mexico, Repertorium Columbianum v. 1 (Los Angeles: UCLA Center for Medieval and Renaissance Studies, 1993), 160.

auh in Españoles no quinvalmina in Mexica in ica tepuzmitl, yoan ic quinvalmotla in tlequiquiztli = from there the Spaniards shot at the Mexica with iron bolts and fired guns at them (Mexico City, sixteenth century)
James Lockhart, We People Here: Nahuatl Accounts of the Conquest of Mexico, Repertorium Columbianum v. 1 (Los Angeles: UCLA Center for Medieval and Renaissance Studies, 1993), 138.