the cartilage under the pit of the stomach (see Molina)
Orthographic Variants:
eltzaqualhuaztli
Alonso de Molina:
eltzaqualhuaztli. la paletilla del estomago. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 29r. col. 1. Thanks to Joe Campbell for providing the transcription.