to blow on something with bellows, or to blow many times (see Molina and Karttunen)
IPAspelling:
pipiːtsɑ
Alonso de Molina:
pipitza. nitla. (pret. onitlapipitz.) follar, o soplarmuchas vezes. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 82r. col. 2. Thanks to Joe Campbell for providing the transcription.
Frances Karttunen:
PIPĪTZ(A) vt to blow on something with bellows, to blow on something repeatedly / follar o soplar muchas veces (M) [(2)Zp.117,193]. redup. PĪTZ(A). Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 197.