Principal English Translation: 

often translated as jaguar, this is a beast; a wild animal; a large animal; a biter of people; something poisonous

Orthographic Variants: 
Alonso de Molina: 

tequani. bestia fiera, o ponzoñosa, o persona brana y cruel.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 104v. col. 2. Thanks to Joe Campbell for providing the transcription.

Frances Karttunen: 

TĒCUĀNI pl: -MEH wild beast / una fiera (C), animal fiero (onza, tigre, león, etc.) (T) The literal sense of this is 'maneater.' See CUĀ.
Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 218.

Lockhart’s Nahuatl as Written: 

a fierce beast, a large predator
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), 234.

Attestations from sources in English: 

Regarding the Nahuatl word tecuani. There is no word for animal in Nahuatl. Nahua speakers use tecuani to name a certain class of living creatures: non-humans that bite. Tecuani does have its root in the verb cua, to eat. But another sense of cua is to bite, and this is the meaning of tecuani, a people biter. Obviously there are some tecuani that, aside from biting people, can also eat them, but this isn't the sense of the word.
John Sullivan, Aztlan Listserv posting, Feb. 29, 2012.

ica oicamac ticalac in tequanj [...] ca ie tequanj icamac = thou hast entered the mouth of a wild beast [...] For already thou art in the mouth of the wild beast (central Mexico, sixteenth century)
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 6 -- Rhetoric and Moral Philosophy, No. 14, Part 7, 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, 1961), 72.

Dances observed by ethnographers in Nahua regions (from Toluca, State of Mexico, to El Salvador) were catalogued by Fernando Horcasitas, including the Danza de los Tigres, which can have the name "Danza de Tecuanes." (twentieth century, Guerrero)
Fernando Horcasitas, "La Danza de los Tecuanes," Estudios de Cultura Náhuatl 14 (1980), 239–286.

tēcuāni = wild animal (colonial Mexico)
Michel Launey, An Introduction to Classical Nahuatl, translated and adapted by Christopher MacKay (Cambridge: Cambridge University Press, 2011), 9.

tequani (noun) = a wild beast, a savage person
Daniel Garrison Brinton, Ancient Nahuatl Poetry: Containing the Nahuatl Text of XXVII Ancient Mexican Poems (1877), 163.

Attestations from sources in Spanish: 

Inin azcatl tecuani. = "Esta hormiga es picadora." "En los dialectos modernos del náhuatl la palabra tecuani se usa como sinónimo de cualquier animal que pica, hace daño o muerde. No se refiere especialmente al tigre o jaguar [i.e. ocelotl], aunque este animal queda incluido por ser dañino. En el Distrito de Necaxa, Sierra de Puebla, se cree que la palabra viene del verbo tecua: 'picar'. Un tecuani es un picador o mordedor." (twentieth century, Puebla)
Fernando Horcasitas, "La Danza de los Tecuanes," Estudios de Cultura Náhuatl 14 (1980), 239–286, see especially p. 252.

IDIEZ morfema: 
IDIEZ traduc. inglés: 
wild or undomesticated animal.
IDIEZ def. náhuatl: 
Ce tlen yoltoc tlen nentinemi zo itztoc cuatitlan huan mahmahui; cequin temahmauhtih huan cequin axcanah. “Nicmelauhqui ce tecuani yalhuaya ne cuatitlan huan axniquittac cualli tlen pampa nimotlaloh chicahuac. ”
IDIEZ morfología: 
tē1, cuā, ni2.
IDIEZ gramática: