xiuhtototl.

Headword: 
xiuhtototl.
Principal English Translation: 

Lovely Cotinga, a bird (see Hunn, attestations)

Attestations from sources in English: 

XIUH-TŌTŌ-TL, literally, “turquoise bird,” Lovely Cotinga (Cotinga amabilis) [FC: 21] Xiuhtototl: “It is an inhabitant of Anahuac, a dweller in Anahuac. It is like all the slender-billed grackles . The bill is pointed, black. Its breast is purple, its back a really light blue, a very light blue, its wings pale, and its tail mixed, part blue-green, part black.” Martin del Campo identified this bird as the Lovely Cotinga. Given the size comparison, one might have expected this to be one of the jays, however, the plumage details do not fit. The Lovely Cotinga is thus the best fit, as its combination of pale blue and deep purple plumage is unique.
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analysis here also appearing in E. S. Hunn, "The Aztec Fascination with Birds: Deciphering Sixteenth-Century Sources," unpublished manuscript, 2022, cited here with permission.

xiuhtototl = the cotinga bird, which has blue feathers
Justyna Olko, Turquoise Diadems and Staffs of Office: Elite Costume and Insignia of Power in Aztec and Early Colonial Mexico (Warsaw: Polish Society for Latin American Studies and Centre for Studies on the Classical Tradition, University of Warsaw, 2005), 129.

Auh ixqujch nenca in tlaҫotototl, y xiuhtototl, in quetzaltototl, i ҫaqua, in tlauhquechol, yoan in ie ixqujch nepapan tototl in cenca vel tlatoa, in vel tepacic cujca = And there dwelt all [varieties of] birds of precious feather—the blue cotinga, the quetzal, the trupial, the red spoonbill, and all the different birds, which spoke very well; which sang right sweetly (central Mexico, sixteenth century)
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 3 -- The Origin of the Gods, Part IV, 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, 1978), 14.

xiuhtototl (noun) = a bird, Guiaca cerulean
Daniel Garrison Brinton, Ancient Nahuatl Poetry: Containing the Nahuatl Text of XXVII Ancient Mexican Poems (1877), 167.

xiuhtototl = cotinga; also the "Turquoise Bird [i.e., the Sun]"
Ballads of the Lords of New Spain: The Codex Romances de los Señores de la Nueva España, transcribed and translated by John Bierhorst (Austin: University of Texas Press, 2009), 31, 35.