the lower cavity of a ship, where water penetrates and accumulates; the bilge (see Molina)
Alonso de Molina:
Acalla yayaliztli. sentina de nauio. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 1v. col. 1. Thanks to Joe Campbell for providing the transcription.