Principal English Translation:
dancing (see Lockhart); also can include singing (see attestations)
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), 227.
Alonso de Molina:
netotiliztli. baile, o danza.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 71r. col. 1. Thanks to Joe Campbell for providing the transcription.
Lockhart’s Nahuatl as Written:
ne-, ihtōtia, -liz-tli. 227
Attestations from sources in English:
John Bierhorst credits James Taggart for saying that netotiliztli serves to refer to a genre that includes both the cantares and the romances (Nahua song traditions from the sixteenth century). This would suggest a broadening of the meaning from simply dancing to include singing -- something to document with attestations in multiple sources. Bierhorst also sees the "flower and song" of the netoltiliztli as relating to "war and music." Flowers are linked to songs and to war. The war cry is also like a bird song or shriek.
Ballads of the Lords of New Spain: The Codex Romances de los Señores de la Nueva España; transcribed and translated from the Nahuatl by John Bierhorst. Austin: University of Texas Press, viii, 38. http://utdi.org/book/index.php?page=songs.phpvmpanti in tenuchca, no vmpanti in tlatilulca, mixnamjctiuj, canca çan yujian, yn netotilo, cenca vel cooamantiuh in netotiliztli = two rows of tenochca and two rows of Tlatelulca facing each other. All danced very slowly; the dance proceeded in harmony. (16th century, Mexico City)
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 2—The Ceremonies, No. 14, Part III, 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, 1951), 54.