huapalli.

Headword: 
huapalli.
Principal English Translation: 

plank, board, small beam (see Molina and Karttunen)

Orthographic Variants: 
uapalli, vapalli, huepalitli
IPAspelling: 
wɑpɑlli
Alonso de Molina: 

uapalli. tabla o viga pequeña.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 154v. col. 2. Thanks to Joe Campbell for providing the transcription.

Frances Karttunen: 

HUAPAL-LI board, small beam / tabla o viga pequeña (M) [(1)Cf.47v,(1)Tp.110,(5)Zp.19,119,154]. In three of five attestations Z marks the vowel of the first syllable long. T has the variant form HUEPAL(I)-TL.
Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 81.

Attestations from sources in English: 

yoan onicaca ichalchiuhcal, yoan iteucujtlacal, yoan itapachcal, yoan iteccizcal, yoan ioapalcal, ixiuhcal, yoan iquetzalcal = And there stood his green stone house, and his golden house, and his coral house, and his shell house, and his house of beams, his turquoise house, and his house of precious feathers (central Mexico, sixteenth century)
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 3 -- The Origin of the Gods, Part IV, eds. and transl. Arthur J. O. Anderson and Charles E. Dibble (Santa Fe and Salt Lake City: School of American Research and the University of Utah, 1978), 13.

sa yca huepalitli oquiquixtiaya ytlan atli = Only with boards did they get [the people?] out of the water.
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), 184–185.

centetl huapalcuezcomatl yyaxca yn nonamictzin catca = a wooden grain bin that belonged to my deceased husband (n.d., sixteenth century)
Testaments of Culhuacan (provisionally modified first edition), eds. Sarah Cline and Miguel León-Portilla, online version http://www.history.ucsb.edu/cline/testaments_of_culhuacan.pdf, 6.

auh in ontetl nohuapal yn ipa nicochi = And the two planks that I sleep on (Culhuacan, 1580)
Testaments of Culhuacan (provisionally modified first edition), eds. Sarah Cline and Miguel León-Portilla, online version http://www.history.ucsb.edu/cline/testaments_of_culhuacan.pdf, 16.

Attestations from sources in Spanish: 

yhuan yn mochi huapaltotonti yhuan cama tlapechtli = y también todas las tablillas, y la cama y tarmia (Xochimilco, 1650)
Vidas y bienes olvidados: Testamentos en náhuatl y castellano del siglo XVII, vol. 3, Teresa Rojas Rabiela, et al, eds. (México: CIESAS, 2002), 248–249.

centetl huapalcuezcomatl ome ixic yhuan centetl cofre yhuan ome metlatl = una troje de tablas que tiene dos portañuelos, y un cofre e dos piedras de moler (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), 144–145.