atlatl.

oncan ye ynpan acico yn oncan chaneque çan no chichimeca oquinmocniuhtitacico yn mexica oncan oquicuitacico yn atlatl auh yn quitemacac yn atlatl ytoca xohuitzil quinmacac yn mexica chichimeca = They arrived among the natives there, who were also Chichimeca. The Mexica made friends with them and there took up the atlatl. And [the natives] gave them the atlatl called xohuitzil; the Chichimeca gave it to the Mexica.
Codex Chimalpahin: Society and Politics in Mexico Tenochtitlan, Tlatelolco, Culhuacan, and Other Nahuatl Altepetl in Central Mexico; The Nahuatl and Spanish Annals and Accounts Collected and Recorded by don Domingo de San Antón Muñón Chimalpahin Quauhtlehuanitzin, eds. and transl. Arthur J. O. Anderson and Susan Schroeder (Norman: University of Oklahoma Press, 1997), vol. 2, 70–71.

iuhquin cozpul ommoteca in impan iaume = When they threw darts with the atlatl, a yellow mass seemed to spread over the enemy
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), 226.

quicuique yn atlatl ynic tlaminaya yaoc = they took up the atlatl with which they shot darts in war
Codex Chimalpahin: Society and Politics in Mexico Tenochtitlan, Tlatelolco, Culhuacan, and Other Nahuatl Altepetl in Central Mexico; The Nahuatl and Spanish Annals and Accounts Collected and Recorded by don Domingo de San Antón Muñón Chimalpahin Quauhtlehuanitzin, eds. and transl. Arthur J. O. Anderson and Susan Schroeder (Norman: University of Oklahoma Press, 1997), vol. 2, 28–29.

ynic tlaxintli tomaoac veyac mamazyo tepoztli yn iquac ca quauhtica ŷ quitlaça = It is fashioned from a thick, long [piece of wood]. It [the dart] has flight feathers; copper is at the tip. They hurled it with the piece of wood.
Fray Bernardino de Sahagún, Primeros Memoriales, ed. Thelma D. Sullivan, et al. (Norman: University of Oklahoma Press, 1997), 276.

¶ viji. acatle xihuitl 1279. años. ypan inyn oncan nauhxiuhtihque mexica yn atlacuihuayan. oncan quinextiliq. yn atlatl = The year Eight Reed, 1279. By this time the Mexica had spent four years in Atlacuihuayan. There they discovered the atlatl (or spear-thrower)
Codex Chimalpahin: Society and Politics in Mexico Tenochtitlan, Tlatelolco, Culhuacan, and Other Nahuatl Altepetl in Central Mexico; The Nahuatl and Spanish Annals and Accounts Collected and Recorded by don Domingo de San Antón Muñón Chimalpahin Quauhtlehuanitzin, eds. and transl. Arthur J. O. Anderson and Susan Schroeder (Norman: University of Oklahoma Press, 1997), vol. 1, 202–203.