behind someone, in his or her absence (see Molina)
Alonso de Molina:
teicampa. detras de alguno, o ensu ausencia. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 94r. col. 2. Thanks to Joe Campbell for providing the transcription.