to suck on something (see Karttunen); to eat or suck on sweet cane (see Molina)
IPAspelling:
pipiːnɑ
Alonso de Molina:
pipina. nitla. (pret. onitlapipin.) comer y chupar cañas dulces. 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:
PIPĪNA vt to suck on something /comer y chupar cañas (M) [(1)Zp.39]. Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 196.