the act of purposefully missing something when weighing that which is sold per pound (see Molina)
Alonso de Molina:
tlachicoxeloliztli. el acto de medir falto lo que se vende por peso. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 117v. col. 1. Thanks to Joe Campbell for providing the transcription.