skull rack (see attestations); also, a name for a tree in Mexico (tzompancuahuitl) is a synonym for tzompantli
Gran Diccionario Náhuatl, citing A. Wimmer 2004. https://gdn.iib.unam.mx/diccionario/tzompancuahuitl/75440 Translated here to English by Stephanie Wood.
"The term 'tzompanteuctli' occurs several times in Annals of Cuauhtitlan. John Bierhorst glosses the word as 'skull rack lord, a high official, or oracle.' He also claims that 'nahuateuctli' ('magician lord') is its synonym. The Annals of Cuauhtitlan tell us that in the year 12 House (1517) Mocteuczoma put to death the skull rack lord (tzompanteuctli) of Cuitlahuac, Quetzalmazatzin, and his sons, after his responding to Mocteuczoma’s question with an answer the latter deemed offensive. According to Bierhorst, Quetzalmazatzin was the oracle who predicted the arrival of the Spaniards."
James Maffie, personal communication, August 20, 2024. He cites: John Bierhorst (trans.), History and Mythology of the Aztecs: The Codex Chimalpopoca. Tucson, AZ: University of Arizona Press, 1992, pp. 124, 125, 139–162, 191, 213, and note 468.