Chichimecatl.

Headword: 
Chichimecatl.
Principal English Translation: 

a Chichimeca, an indigenous inhabitant of the North of Mexico; an ancestor of the Mexica; or, someone considered a barbarian
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), 214.

IPAspelling: 
tʃiːtʃiːmeːkɑtɬ
Frances Karttunen: 

chi:chi:me:ca-tl CHĪCHĪMĒCA-TL pl: CHĪCHĪMĒCAH Chichimec, a person from one of the indigenous groups of northern Mexico considered barbarians by Nahuatl speakers. / Chichimeco de nación (C) Used as a modifier, this has both a negative ‘barbarous’ sense and a positive ‘noble savage’ sense. By its vowel length pattern it is clearly not derived from the words for ‘dog,’ ‘rags, patches,’ or ‘bitter.’ It is possibly derivationally related to CHĪCHĪ ‘to suckle.’
Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 48.

Lockhart’s Nahuatl as Written: 

abs. pl. chīchīmēcah. from a place name Chīchīmān, -(m)ēcatl inhabitant of a place or unit whose name ends in -mān.
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), 214.

Attestations from sources in English: 

huehue Aculmiztli chichimecatl teuhctlato ynteyacancauh catca yn aculhuaque. yn cuhuatl ychan tlaca. auh yehuatl in quauhtzonyotl mochihuaco yn tlahtocatlacamecayotica yn vmpa cohuatl ychan. = Huehue Acolmiztli Chichimecatl was [then] a subordinate ruler and leader of the Acolhuaque and people of Coatl Ichan. And he became the lineage [head] of the line of rulers of Coatl Ichan. (central Mexico, early seventeenth century)
Codex Chimalpahin: Society and Politics in Mexico Tenochtitlan, Tlatelolco, Culhuacan, and Other Nahuatl Altepetl in Central Mexico; The Nahuatl and Spanish Annals and Accounts Collected and Recorded by don Domingo de San Antón Muñón Chimalpahin Quauhtlehuanitzin, eds. and transl. Arthur J. O. Anderson and Susan Schroeder (Norman: University of Oklahoma Press, 1997), vol. 2, 110–111.

yn manel Otontzintli ynmanel chichimecatl yn amo yximachoni yn amo maviztililoni yn ça ça vel tlapaltzitzintin yn motoliniani = although it be a [simpleminded] little Otomí or a [wild savage] Chichimec who is unknown and dishonorable, who are just really ordinary fellows, the poor.
Fray Alonso de Molina, Nahua Confraternities in Early Colonial Mexico: The 1552 Nahuatl Ordinances of fray Alonso de Molina, OFM, ed. and trans., Barry D. Sell (Berkeley: Academy of American Franciscan History, 2002), 134–135.

Tlā cuēl! Tlā xihuāllauh, Tlātlāhuic Chīchīmēcatl = Let it be soon! Come, Red Chichimec [i.e., the ax].
(Atenango, between Mexico City and Acapulco, 1629)
Hernando Ruiz de Alarcón, Treatise on the Heathen Superstitions That Today Live Among the Indians Native to This New Spain, 1629, eds. and transl. J. Richard Andrews and Ross Hassig (Norman and London: University of Oklahoma Press, 1984), 87.

oncan in quiminque ce covatl cenca tomahuac ce chichimecatl = There they shot a very thick snake with arrows; it was a Chichimeca who shot it.
Codex Chimalpahin: Society and Politics in Mexico Tenochtitlan, Tlatelolco, Culhuacan, and Other Nahuatl Altepetl in Central Mexico; The Nahuatl and Spanish Annals and Accounts Collected and Recorded by don Domingo de San Antón Muñón Chimalpahin Quauhtlehuanitzin, eds. and transl. Arthur J. O. Anderson and Susan Schroeder (Norman: University of Oklahoma Press, 1997), vol. 1, 24–25.

In Ocotelulco, in 1598, we see a person named Chichimecatzin. (See the examples from Spanish sources.)

Attestations from sources in Spanish: 

Auh in axcan niconmaquilitiuh yn nicauhtzin ytepanco opeua Chichimecatzin yn occecapal ytepanco Basqual = Y agora se la doy a mi hermano menor, a la linde de Chichimecatzin, y por otra parte a la linde de Pascual
Vidas y bienes olvidados: Testamentos indígenas novohispanos, vol. 1, Testamentos en castellano del siglo XVI y en náhuatl y castellano de Ocotelulco de los siglos XVI y XVII, eds. Teresa Rojas Rabiela, Elsa Leticia Rea López, y Constantino Medina Lima (Santa Bárbara, Tamasolco, Tlaxcala, 1598), 304-305.

auh çeiohual quimitaque chichimecuicaia, quiahualoa imomos = Toda la noche se les vió cantando sus cantos chichimecas, dando vueltas alrededor de su altar (Mexico City, c. 1572)
Ana Rita Valero de García Lascuráin and Rafael Tena, Códice Cozcatzin (México: Instituto Nacional de Antropología e Historia, Benemérita Universidad Autónoma de Puebla, 1994), 103.