to rave, talk nonsense, be delerious (see Molina)
yolmalacachiui. ni. (pret. oniyolmalacachiuh.) deuanear. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 41r. col. 1. Thanks to Joe Campbell for providing the transcription.