a discount of something that is owed, giving or paying something for another (see Molina)
ipam poliuiztli. lo mismo es que ipan poliuiliztli. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 41v. col. 1. Thanks to Joe Campbell for providing the transcription.