Principal English Translation:
to cook something in a pot, boil it
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), 229.
Alonso de Molina:
pauaci. nitla. (pret. onitlapauaz.) cozer algo en olla, o en cosa semejante.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 80v. col. 1. Thanks to Joe Campbell for providing the transcription.
Frances Karttunen:
PĀHUAC(I) vt; prel: PĀHUAZ to cook something in a pot, to stew something / cocer algo en olla o en cosa semejante (M) [(7)Cf.46v,62v,64r]. The initial syllable of this is probably cognate with Ā-TL 'water, liquid' and preserves the Proto-Uto-Aztecan initial *P. PĀHUAXILIĀ applic. PĀHUAC(I).
Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 185.
Lockhart’s Nahuatl as Written:
nic. Class 2: ōnicpāhuaz, pā- is a root meaning water and by origin the same as ātl. 229
Attestations from sources in English:
auh ça tzohoalli, inic quixiptlaioti, in ipan quipouh: tlaolpaoastli ipan quitlatlali, inic quitequalti = And they made [the victim's] image of pure amaranth seed dough, so that it might represent him; they set cooked grains of maize upon it, so that they could give it to the people to eat. (central Mexico, sixteenth century)
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 7 -- The Sun, Moon, and Stars, and the Binding of the Venus, No. 14, Part VIII, 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), 31.