admit, confess to something, or to recognize what has been done (see Molina)
Alonso de Molina:
ic niteixmotla. (pret. ic oniteixmotlac.) lo mismo es que ixcomaca. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 33r. col. 1. Thanks to Joe Campbell for providing the transcription.