something figurative or traced with three angles, or corners (see Molina)
Alonso de Molina:
yexcampa tlamachiotili. figurada o trazada cosa assi. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 36r. col. 2. Thanks to Joe Campbell for providing the transcription.