an expression made to get someone's attention (see Molina)
Alonso de Molina:
netle. ola, hao, oys, para llamar a alguno. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 70v. col. 2. Thanks to Joe Campbell for providing the transcription.