don.

(a loanword from Spanish)

Headword: 
don.
Principal English Translation: 

don, a title of nobility
(a loanword from Spanish)

Lockhart’s Nahuatl as Written: 

honorific title, like Sir. Sp.
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), 235.

Attestations from sources in English: 

"A title of high nobility, received primarily through birthright, prefaced to an individual's first name and used invariably on all occasions from birth to death; usage among Indians was related but not identical."
The Tlaxcalan Actas: A Compendium of the Records of the Cabildo of Tlaxcala (1545–1627), eds. James Lockhart, Frances Berdan, and Arthur J.O. Anderson (Salt Lake City: University of Utah Press, 1986), 153.

don julian... don juan mascin... don frco de mendoça (Tlaxcala, 1547)
Beyond the Codices, eds. Arthur J.O. Anderson, Frances Berdan, and James Lockhart (Los Angeles: UCLA Latin American Center, 1976), Doc. 21.

ocotelulco allde don julian de la rosa (Tlaxcala, 1547)
Beyond the Codices, eds. Arthur J.O. Anderson, Frances Berdan, and James Lockhart (Los Angeles: UCLA Latin American Center, 1976), Doc. 22.

in don juan (Coyoacan, 1548)
Frances Karttunen and James Lockhart, Nahuatl in the Middle Years: Language Contact Phenomena in Texts of the Colonial Period, Linguistics 85 (Los Angeles, University of California Publications, 1976), Doc. 1.

y ni don juo .. don pablo çacancacintli ... don luys acuecuexco (Coyoacan, before July 1549) Beyond the Codices, eds. Arthur J.O. Anderson, Frances Berdan, and James Lockhart (Los Angeles: UCLA Latin American Center, 1976), Doc. 17.

Attestations from sources in Spanish: 

Yhuan nehuatl ton Juan Pelnaltino ca nicchihua notextamento = Y yo ahora don Juan Bernardino que hago este mi testamento (Zempoala, "1610", but probably Techialoyan -related)
Vidas y bienes olvidados: Testamentos en náhuatl y castellano del siglo XVII, vol. 3, Teresa Rojas Rabiela, et al, eds. (México: CIESAS, 2002), 76–77.