something that is dirty, repugnant or that smells rotten (the smell of death/decomposition) (see Molina)
Alonso de Molina:
miquiz hiyaltic. cosa hedionda o que hiede a cosas muertas y podridas. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 56v. col. 2. Thanks to Joe Campbell for providing the transcription.