the commissioning of someone to guard a secret or some piece of property for someone else (see Molina)
Alonso de Molina:
tetlapialtiliztli. encomienda de secreto o de hazienda que se da a guardar a otro. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 109r. col. 1. Thanks to Joe Campbell for providing the transcription.