to make a hole or open a well (see Molina)
atlacomuloa. n. (pret. onatlacomulo.) hazer hoyo o pozo. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 8r. col. 1. Thanks to Joe Campbell for providing the transcription.