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), 230.
IPAspelling:
piyɑ
Frances Karttunen:
PIY(A) vrefl, vt; pret: PIX ~ PĪX to protect oneself from something; to take care of someone or something, to have steward-ship of something, to hold something / guardarse de algo (M), guardar a otro (M), guardar alguna cosa (M) T consistently has a short I throughout the verbal paradigm, and Z has a long vowel. B and C have a short vowel throughout except in the preterit, where the I is followed by X. In these cases the vowel is sporadically marked long. The incidence of TLAHPIY(A) implies a virtually synonymous derived verb (I)HPIY(A). A common variant of PIY(A) is PIY(E). PIYALŌ nonact. PIY(A). PIY(E) See PIY(A). Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 199.