1) an ethnicity, a person from Tlapallan
Gran Diccionario Náhuatl, citing Wimmer 2004, https://gdn.iib.unam.mx/diccionario/tlapaltecatl
2) a person's name (attested as male) -- there was a member of the elite by this name, don Pedro Tlapaltecatl, son of Machimalle (who was possibly a son of Axayacatzin) (central Mexico, seventeenth century)
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, 104–105.