pepetztic. cosa muy lisa que reluze. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 80v. col. 2. Thanks to Joe Campbell for providing the transcription.
Frances Karttunen:
PEHPETZTIC something smooth, shiny / cosa muy alisa que reluce (M) [(2)Tp.123,173, (I)Xp.63]. M has pepetzca 'for silk or fine plumage to shimmer.' redup. PETZTIC. Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 191.