to block or close the road or path (see Molina)
otlaza. n. (pret. onotlaz.) cegar, o cerrar camino. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 78r. col. 1. Thanks to Joe Campbell for providing the transcription.