to take something away from the load another person carries, so that the load will not weigh as much
Alonso de Molina:
tzoncuilia. nitetla. (pret. onitetlatzoncuili.) quitar algo dela carga que otro lleua acuestas, paraque no pese tanto. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 153r. col. 2. Thanks to Joe Campbell for providing the transcription.