tzopilotl.

Headword: 
tzopilotl.
Principal English Translation: 

Turkey Vulture and Black Vulture, birds (see Hunn, attestations)

IPAspelling: 
tsopiːloːtɬ
Alonso de Molina: 

tzopilotl. aura.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 153v. col. 2. Thanks to Joe Campbell for providing the transcription.

Frances Karttunen: 

TZOPĪLŌ-TL pl: -MEH buzzard / aura (M), zopilote, águila (T), zopilote de cabeza negra (X) [(1)Tp.244, (2)Zp.132,226, (3)Xp.98].
Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 319.

Lockhart’s Nahuatl as Written: 

abs. pl. sometimes tzōtzopīlōmeh. seems to contain tzotl, offal.
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), 241.

Attestations from sources in English: 

TZOPĪLŌ-TL, Turkey Vulture (Cathartes aura) and Black Vulture (Coragyps atratus) [FC: 42 Tzopilotl] “It is black, dirty black, chili-red-headed, chalky-legged. All its food is what has died – stinking, filthy.” This describes the Turkey Vulture, though Martin del Campo gives priority to the Black Vulture. The name apparently applied equally to both species. Clearly, the Aztecs shared our modern sensibilities with respect to these carrion feeders.
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 11 – Earthly Things, no. 14, Part XII, 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, 1963); Rafael Martín del Campo, “Ensayo de interpretación del Libro Undecimo de la Historia General de las Cosas de Nueva España de Fray Bernardino de Sahagún – 11 Las Aves (1),” Anales del Instituto de Biología Tomo XI, Núm. 1 (México, D.F., 1940); and, with quotation selections, synthesis, and analysis here also appearing in E. S. Hunn, "The Aztec Fascination with Birds: Deciphering Sixteenth-Century Sources," unpublished manuscript, 2022, cited here with permission.

Taken into Spanish as zopilote.

tzopilotl = buzzard, vulture
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), 241.

auh y tototzitzintin yn cacalome yn tzotzo pilo[me] [f. 30v] niman muchin tlalpan huetzque ça papatlacatinemia huel otlaocoltzatzatzique = and the little birds, the crows, the buzzards, all fell on the ground and went about fluttering and making very mournful cries
Here in This Year: Seventeenth-Century Nahuatl Annals of the Tlaxcala-Puebla Valley, ed. and transl. Camilla Townsend, with an essay by James Lockhart (Stanford: Stanford University Press, 2010), 154–155.

Tepal nitzopiloti. = With someone's help I became a vulture.
Thelma D. Sullivan, "Nahuatl Proverbs, Conundrums, and Metaphors, Collected by Sahagún," Estudios de Cultura Náhuatl 4 (1963), 116–117.

Attestations from sources in Spanish: 

Inic ompa mochihuaz in tzopilome, in cocoyo (...) Inic itzcuintli intlacual momochihuaz. Yehica ayac oquitochtli, oquimazatili; ca zan inehuian oquimochihuili, oquimopicti in acualli, in ayectli, in tlahuelilocayotl = En esta forma se hará comida de los zopilotes, de los coyotes (...) De este modo se hará comida de perro. Porque nadie lo hizo conejo, lo hizo venado; que sólo él mismo se hizo, se formó malo, torcido, maldoso (centro de México, s. XVI)
Josefina García Quintana, "Exhortación de un padre a su hijo; texto recogido por Andrés de Olmos," Estudios de Cultura Náhuatl 11 (1974), 156–157.

Inic vmpa intlaqual muchihuaz in tzopilome, in cocoyo = Allá se convertirá en comida de los zopilotes, de los coyotes
Huehuehtlahtolli. Testimonios de la antigua palabra, ed. Librado Silva Galeana y un estudio introductorio por Miguel León-Portilla (México: Secretaría de Educación Pública, Fondo de Cultura Económica, 1991), 56–57.