for something to become manifest that was once known in secret (see Molina)
Alonso de Molina:
mixquetza. manifestarse lo que se sabia en secreto. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 57r. col. 2. Thanks to Joe Campbell for providing the transcription.