to find out something about a friend (see Molina); an applicative form of ixpantia; also, in the reflexive, for something to present or manifest itself (see Karttunen)
IPAspelling:
iːʃpɑntiliɑː
Alonso de Molina:
ixpantilia. nitetla. vel. nicte. (pret. onitetlaixpantili.) descubrir algo al amigo. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 46v. col. 1. Thanks to Joe Campbell for providing the transcription.
Frances Karttunen:
ĪXPANTILIĀ applic. ĪXPANTIĀ
ĪXPANTIĀ vrefl, vt for something to present, manifiest itself; to present, reveal, confide something / se presenta (T), proponer, manifestar, o dar noticia de algún negocio a otros (M), descubrir algo al amigo (M), lo revela (T) [(6)Tp.143,217]. See –ĪXPAN. Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 117.