tlanextli.

Headword: 
tlanextli.
Principal English Translation: 

light, radiance
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), 237.

Orthographic Variants: 
tlanēxtli
IPAspelling: 
tɬɑneːʃtɬi
Alonso de Molina: 

tlanextli. luz, claridad o resplandor.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 128v. col. 2. Thanks to Joe Campbell for providing the transcription.

Frances Karttunen: 

TLANĒX-TLI light, radiance / luz, claridad, o resplandor (M) See TLANĒC(I).
Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 285.

Lockhart’s Nahuatl as Written: 

patientive noun from some verb form related to nēci. 237

Attestations from sources in English: 

in yancuic tonatiuh in yancuic tlanextli = the new sun, the new light (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, 152–153.

yn tlaçotlanextzintli in mochpochxillantzinco = the precious light that is in your maidenly womb (early seventeenth century, Central Mexico)
Louise M. Burkhart, Before Guadalupe: The Virgin Mary in Early Colonial Nahuatl Literature, Institute for Mesoamerican Studies Monograph 13 (Albany: University at Albany, 2001), 55.

tlanēxtli = window opening
Berenice Alcántara and Pedro A. Muñoz, "'You Here, Don't Do It This Way': Allegory and Domestic Dwellings in Bernardino de Sahagún's Nahuatl Sermons of the House," Ethnohistory 71:2 (April 2024), see p. 149.