mamalhuaztli.

Headword: 
mamalhuaztli.
Principal English Translation: 

a constellation, which Molina calls "sticks of wood," but which is possibly Orion's Belt (see Molina); Sahagún identifies the constellation as "the wands of the sky , which are near the Pleiades, a group of stars in Taurus," and Tezozomoc called the constellation the Keys of St. Peter (clearly drawing from a European source); also, this is a hand tool or drill for making fire, and a backpack or frame for carrying things; finally, a pectoral
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), 224.

Orthographic Variants: 
Mamalhoaztli
IPAspelling: 
mɑːmɑlwɑːstɬi
Alonso de Molina: 

mamalhuaztli. astillejos, constelacion.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 52r. col. 1. Thanks to Joe Campbell for providing the transcription.

Frances Karttunen: 

MĀMALHUĀZ-TLI gear for carrying something on the shoulders / mochila (K) [(1)Bf.3V]. This is paired with CUEXĀN-TLI ‘packing bags,’ the whole phrase meaning ‘under the protection of someone’ M has mamalhuaztli ‘the constellation of Castor and Pollux’ (literally ‘the Drill’), which would contrast with this item in vowel length of the first syllable. See TLAMĀMAL-LI, MĀMĀ
Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 135.

Lockhart’s Nahuatl as Written: 

māmalhuāztli. backpack for carrying things. -cuexānco -māmalhuāzco, under someone's protection. patientive noun from māmā plus huāztli tool.
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), 224.

Attestations from sources in English: 

Mamalhoaztli = The Fire Drill (central Mexico, sixteenth century) Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 7 -- The Sun, Moon, and Stars, and the Binding of the Venus, No. 14, Part VIII, 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, 1961), 11.

cuix àmo nocuixanco nomamalhuazco = Are you not in the security of my lapfold, in my carrying gear? (Mexico City 1649)
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), 205.

Attestations from sources in Spanish: 

mamalhuaztli tehtetenqui = colcha de tableros (Amecameca, 1625)
Vidas y bienes olvidados: Testamentos en náhuatl y castellano del siglo XVII, vol. 3, Teresa Rojas Rabiela, et al, eds. (México: CIESAS, 2002), 162–163.

yhuan ynin tlaococolilocatzin pipiltzitzinti centetl mamalhuaztli sahuanilla ome mantilla ce = y unos obsequios para mis hijos: un pectoral, dos sabanillas y una mantilla (Coyoacán, 1624)
Vidas y bienes olvidados: Testamentos en náhuatl y castellano del siglo XVII, vol. 3, Teresa Rojas Rabiela, et al, eds. (México: CIESAS, 2002), 144–145.

Yhuan quihualhuicaya quitohuaya chicuinahui mamalhuiztl in tletl yn ihuitzinan = Y traían nueve de los llamados mamalhuaztli, que son intrumentos para hacer fuego (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), 88–89.

themes: 
Celestial Phenomena
Fire, Tobacco, Incense
Metaphors, Proverbs, Riddles
Religion (Indigenous)
Technology, Tools