for water to spurt, or for a lot of water to fall from above (see Molina)
Alonso de Molina:
mopiloa. (pret. omopilo.) chorrear o caer de alto el chorro de agua Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 059v. col. 2. Thanks to Joe Campbell for providing the transcription.