atlacayotl. inhumanidad o crueldad. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 8r. col. 1. Thanks to Joe Campbell for providing the transcription.
Frances Karttunen:
AHTLĀCAYŌ-TL cruelty, inhumanity / inhumanidad o crueldad (M)[(1)Rp.62]. See AHTLĀCA-TL. Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 7.