nanahuatl.

Headword: 
nanahuatl.
Principal English Translation: 

pustules; a sign of venereal disease
Fray Bernardino de Sahagún, Primeros Memoriales, ed. Thelma D. Sullivan (Norman: University of Oklahoma Press, 1997), 283.

Orthographic Variants: 
nanauatl
IPAspelling: 
nɑːnɑːwɑtɬ
Alonso de Molina: 

nanauatl. bubas.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 063r. col. 1. Thanks to Joe Campbell for providing the transcription.

Frances Karttunen: 

NĀNĀHUA-TL bubo, swollen gland / bubas (M) [(2)Rp.108]. This is attested without diacritics in R. Z's NĀNĀHUACOCO-TL suggests long vowels in the first two syllables.
Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 159.

Attestations from sources in English: 

"the Indian disease which the natives call nanahuatl (which infected the entire globe)" ("a venereal disease") (Central Mexico, 1571–1615)
The Mexican Treasury: The Writings of Dr. Francisco Hernández, ed. Simon Varey, transl. Rafael Chabrán, Cynthia L. Chamberlin, and Simon Varey (Stanford: Stanford University Press, 2000), 70.

a sick and pustulous person, Nanāhuatzin, they give this name to the man converted into the sun (Atenango, between Mexico City and Acapulco, 1629)
Hernando Ruiz de Alarcón, Treatise on the Heathen Superstitions That Today Live Among the Indians Native to This New Spain, 1629, eds. and transl. J. Richard Andrews and Ross Hassig (Norman and London: University of Oklahoma Press, 1984), 71.