ecamalacotl.

Headword: 
ecamalacotl.
Principal English Translation: 

a whirlwind, tornado (see Molina); dustdevil (see Karttunen); also, attested as a name (male)

IPAspelling: 
ehkɑmɑlɑkoːtɬ
Alonso de Molina: 

ecamalacotl. remolino de viento.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 28r. col. 1. Thanks to Joe Campbell for providing the transcription.

Frances Karttunen: 

EHCAMALACŌ-TL dust devil / remolinito (T) [(1)Tp.249]. The first element of this seems to have lost a syllable, and the final syllable has the reflex of Ō instead of expected A. See EHĒCA-TL, MALACA-TL.
Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 75.

Attestations from sources in English: 

A person of the Nahua nobility named Huiznahuatl Ecamalacotl was sentenced for adultery and executed by stoning in front of a large crowd, according to the Florentine Codex.
Pilar Máynez, El calepino de Sahagún: un acercamiento (México: Universidad Nacional Autónoma de México, 2002), 130. She cites Book 8, fol. 27, 277 recto.

At least two names in the Matrícula de Huexotzinco are Ecamalacotl. See one here: https://aztecglyphs.wired-humanities.org/content/ecamalacotl-mh497r In this one and another, the ecamalcotl seems to be an apparatus that spins in the wind.

mjn hecamalacotl = Martín Ecamalacotl; elsewhere spelled: mjn hecamalacatl = Martín Ecamalcatl (It is not clear if this is the same name, given the final a and the name glyph having a spindle in the midst of wind.) (Tepetlaoztoc, sixteenth century)
Barbara J. Williams and H. R. Harvey, The Códice de Santa María Asunción: Facsimile and Commentary: Households and Lands in Sixteenth-Century Tepetlaoztoc (Salt Lake City: University of Utah Press, 1997), 86–87, 120–121, 122.