potoni.

Headword: 
potoni.
Principal English Translation: 

to stink or smell bad (see Molina); can relate to the weather and dust storms

IPAspelling: 
potoːni
Alonso de Molina: 

potoni. ni. (pret. onipoton.) heder, o oler mal.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 83v. col. 1. Thanks to Joe Campbell for providing the transcription.

Frances Karttunen: 

POTŌN(I) to stink / heder o oler mal (M) [(3)Cf.49r]. T has this compounded with TLĀL-LI with the sense of 'for it to be dusty (weather).' This would appear to be a homophonous but separate item, yet M provides a gloss about dust for related POTŌNQUI.
Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 203.

Attestations from sources in English: 

icemihyayaliz, in icempotoniliz = it will stink
Susanne Klaus, Uprooted Christianity: The Preaching of the Christian Doctrine in Mexico, Based on Franciscan Sermons of the 16th Century Written in Nahuatl (Bonn: Bonner Amerikanistische Studien e. V. c/o Seminar für Völkerkunde, Universität Bonn, 1999), 249.

potonj (potoni) = it stinks (central Mexico, sixteenth century)
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 10 -- The People, No. 14, Part 11, 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), 133.

Attestations from sources in Spanish: 

xali yn icpac quisaya tepetl ynic potonia yuhqui polpra = cayó arena que salía de la cima de la montaña y olía como pólvora (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 and México: Universidad Autónoma de Tlaxcala, Secretaría de Extensión Universitaria y Difusión Cultural, y Centro de Investigaciones y Estudios Superiores en Antropología Social, 1995), 342–343.