huepantli.

Headword: 
huepantli.
Principal English Translation: 

a large rough-hewn wooden beam
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), 218.

Orthographic Variants: 
huapantli, uepantli, huepamitl
Alonso de Molina: 

uepantli. viga grande desbastada y por labrar.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 156v. col. 2. Thanks to Joe Campbell for providing the transcription.

Frances Karttunen: 

HUEHPĀM(I)-TL a large hewn beam / viga grande desbaratada y por labrar (M), las vigas (C) [(1)Cf.93r]. M has the form vepantli. See HUĒ(I), PĀM(I)-TL.
Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 84.

Lockhart’s Nahuatl as Written: 

huēi, pāntli as in tepāntli.
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), 218.

Attestations from sources in English: 

vme vepantli quitlecavica, yoan miec in aoaquavitl, mimimiltic; itoca, teuquavitl in quitlecavique, in impan quioallaçazquia = they took up two large beams and many round oak logs called "god wood" that they were going to hurl down on [the Spaniards].
Mexico City, sixteenth century) James Lockhart, We People Here: Nahuatl Accounts of the Conquest of Mexico, Repertorium Columbianum v. 1 (Los Angeles: UCLA Center for Medieval and Renaissance Studies, 1993), 146.

Attestations from sources in Spanish: 

onictlapachilhuito ce huapatli nicmacac yhuan mochin quauhtectli ynic tlamito yhuan mochi yn tlaxamanili ynic huel motlapacho = le teché, le di la plancha y morillos y le cubrí la casa (Coyoacan, 1607)
Vidas y bienes olvidados: Testamentos en náhuatl y castellano del siglo XVII, vol. 3, Teresa Rojas Rabiela, et al, eds. (México: CIESAS, 2002), 56–57.

yquac quauhtla calacohuac huepanaloto = entraron al bosque, fueron por vigas (ca. 1582, México)
Luis Reyes García, ¿Como te confundes? ¿Acaso no somos conquistados? Anales de Juan Bautista (Mexico: Centro de Investigaciones y Estudios Superiores en Antropología Social, Biblioteca Lorenzo Boturini Insigne y Nacional Basílica de Guadalupe, 2001), 164.