to be astonished or to be astounded with fright (see Molina)
Alonso de Molina:
iuhcantlamati. n. (pret. oniuhcantlamat.) embazar o estar atonito de espanto. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 43v. col. 1. Thanks to Joe Campbell for providing the transcription.