macihui.

Headword: 
macihui.
Principal English Translation: 

even though, although, granted that, given that (see Molina and Karttunen)

Orthographic Variants: 
maciui, maçoiui, maçoihui, maçoyhui, maçihui
IPAspelling: 
mɑːsiwi
Alonso de Molina: 

maciui. aunque, o dado que, o puesto caso
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 50v. col. 2. Thanks to Joe Campbell for providing the transcription.

Frances Karttunen: 

MĀCIHUI although, granted that / aunque o dado que o puesto caso (M) This is attested once in B with MAH in place of MĀ , but it is clearly a shortened form of MĀZO IHUI. See MĀZO, IHU(I).
Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 128.

Horacio Carochi / English: 

mācihui = although
Horacio Carochi, S.J., Grammar of the Mexican language with an explanation of its adverbs (1645), translated and edited with commentary by James Lockhart, UCLA Latin American Studies Volume 89 (Stanford: Stanford University Press, UCLA Latin American Center Publications, 2001), 506.

Attestations from sources in English: 

auh in maçihui in ticyta in yca in totlacatlachializ in tlaxcalli neçi, ca aocmo tlaxcalli in oncan ca, ca çan huel tehuatl in inacayotzin, ça ixquich in tlaxcalnenezcayotl = And even though with our human eyes we see that it appears to be bread, what exists is no longer bread but His very body; it is all just the appearances of bread
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), 147.

maciui (adverb) = although, granted that
Daniel Garrison Brinton, Ancient Nahuatl Poetry: Containing the Nahuatl Text of XXVII Ancient Mexican Poems (1877), 157.

Attestations from sources in Spanish: 

auh in maçihui in ticyta in yca in totlacatlachializ in tlaxcalli neçi, ca aocmo tlaxcalli in oncan ca, ca çan huel tehuatl in inacayotzin, ça ixquich in tlaxcalnenezcayotl = Y avnque le ven los ojos del cuerpo, que parece pan, ya no es pan lo que queda alli, sino su verdadero cuerpo, solos los accidentes, y apariencias de pan quedan, debaxo de los quales está escondido y oculto. Por dos cosas
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), 146–147.

maçoyhui ynimococoua ca ça yeuatl ynotlalo auh ynanima yuan ynoceyaliz ca huel pactica = aunque estoy mala en cuanto a mi cuerpo, en cuanto a mi alma y voluntad estoy muy buena (Santa Bárbara Maxoxtlan, 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), 216–217.