the roundness of something round, such as the moon or a shield (see Molina)
Orthographic Variants:
teuilacachiuhcayotl
Alonso de Molina:
teuilacachiuhcayotl. redondez de cosa redonda assi como de rodela, o luna. &c. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 112r. col. 1. Thanks to Joe Campbell for providing the transcription.