iglesia.

(a loanword from Spanish)

Headword: 
iglesia.
Principal English Translation: 

church

Orthographic Variants: 
eclesea, yglesia, yglecia, ygelcia, yglexia, yglessia, ylecia, cleçia
Lockhart’s Nahuatl as Written: 

iglēsiah. church. generally the entire Christian church, not a building; often occurs with usual Sp. modifiers, such as holy, Catholic, Roman, etc. 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), 220.

Attestations from sources in English: 

tonantz̄in sancta yglesia = our mother the holy Church (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, 130–131.

"Santa iglesia" was a fairly common loanword in colonial Nahuatl. Alva's guide to confession uses it 10 times out of 260 total loanword appearances of various kinds. The percentages of appearances of certain loans in Alva are very consistent with Chimalpahin, who also wrote in the seventeenth century.
See Sell's comments in Bartolomé de Alva, A Guide to Confession Large and Small in the Mexican Language, 1634, eds. Barry D. Sell and John Frederick Schwaller, with Lu Ann Homza (Norman: University of Oklahoma Press, 1999), 23.

"Through most of the text the word for cathedral is iglesia mayor, main church, which Spaniards in all parts of the Indies had used in that sense up to this time. But in the last part of the text the loanword catedral appears, and after a brief transition it becomes predominant, surely reflecting the fact that the Spanish comunity of that time was adopting the more specific and pretentious word."
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), 49.

ca yoqui techmonahuatiLia sancta ecLesea yhuan teopixquime saserdotis = thus the holy church and the priestly minister admonish us (Zacualco/Tzacualco, 1629)
Beyond the Codices, eds. Arthur J.O. Anderson, Frances Berdan, and James Lockhart (Los Angeles: UCLA Latin American Center, 1976), Doc. 31, 196–197.

nehual nifiscal de la madre santi yglesia = I am the fiscal of the holy mother church (Santa María de la Asunción, Toluca Valley, 1758)
Caterina Pizzigoni, ed., Testaments of Toluca (Stanford: Stanford University Press and UCLA Latin American Center Publications, 2007), 185.

teopan yglesia yxpan crucifixo tecalco (Tlaxcala, 1566)
Beyond the Codices, eds. Arthur J.O. Anderson, Frances Berdan, and James Lockhart (Los Angeles: UCLA Latin American Center, 1976), Doc. 1.

15 pos 2 to quihuiquilia huey yglesia yhuan ce caxa yyaxca sancto sacramento (Jalostotitlan, Jalisco, 1611)
Beyond the Codices, eds. Arthur J.O. Anderson, Frances Berdan, and James Lockhart (Los Angeles: UCLA Latin American Center, 1976), Doc. 27.

santa yglexia (San Juan Tolcayuca, Hidalgo)
A late colonial, Techialoyan manuscript in the Kislak Collection; f. 5r.

fisCal de Sata gelessia = fiscal of the holy church (San Pablo Tepemaxalco, Toluca Valley, 1736)
Caterina Pizzigoni, ed., Testaments of Toluca (Stanford: Stanford University Press and UCLA Latin American Center Publications, 2007), 155.

la santa mader gelesian = the holy mother church (San Lucas, Evangelista, Toluca Valley, 1759)
Caterina Pizzigoni, ed., Testaments of Toluca (Stanford: Stanford University Press and UCLA Latin American Center Publications, 2007), 164.

Attestations from sources in Spanish: 

in oncan quiҫaz yn intlaqual teopixque yvan in tlein monequi yglesia yvan in ilhuitlipan in tlein monequi anoҫo altepetl ytech monequi ca nel yc mitova altepetl i yaxca = de ahí saldrá la comida de los padres; lo que se necesita en la iglesia y en las fiestas; lo que sea necesario o se requiera para el pueblo; ya que de verdad por esto se le nombra propiedad del pueblo. (Cuauhtinchan, Puebla, s. XVI)
Luis Reyes García, "Ordenanzas para el gobierno de Cuauhtinchan, año de 1559," Estudios de Cultura Náhuatl 10 (1972), 294–295.

ma ymochihua yn santa ylecia = se haga en la santa iglesia (San Juan Teotihuacan, 1563)
Vidas y bienes olvidados: Testamentos indígenas novohispanos, vol. 2, Testamentos en náhuatl y castellano del siglo XVI, eds., Teresa Rojas Rabiela, Elsa Leticia Rea López, Constantino Medina Lima (Mexico: Consejo Nacional de Ciencias Tecnología, 1999), 130–131.

nitlanauatia centetl nocavallo quinamacazque yn quen ipatiuh ma yuh oquicuizque santa ygresia monequiz = tengo un caballo, que lo vendan y de su valor que tome de lo que se necesite en la santa iglesia (Santa Agueda, sin fecha)
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 (Mexico: CIESAS, 1999), 202–203.

yhuan quitlatoctique ynic pilca quahuitl tepozmecatl yni quitecuixque oca quicema yn itequi ynic tlatequipanohua Santa cleçia = Y para asegurarla a la viga donde cuelga, la liaron con cables de metal. Con ella señalan la labor que es el trabajo de la Santa Iglesia (Tlaxcala, 1662–1692)
Juan Buenaventura Zapata y Mendoza, Historia cronológica de la Noble Ciudad de Tlaxcala, transcripción paleográfica, traducción, presentación y notas por Luis Reyes García y Andrea Martínez Baracs (Tlaxcala y México: Universidad Autónoma de Tlaxcala, Secretaría de Extensión Universitaria y Difusión Cultural, y Centro de Investigaciones y Estudios Superiores en Antropología Social, 1995), 316–317.