a holiday, a calendrical celebration that is observed regularly (see Molina)
Orthographic Variants:
pieloni yihuitl [sic]
Alonso de Molina:
pieloni yihuitl [sic?]. fiesta de guardar. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 81v. col. 1. Thanks to Joe Campbell for providing the transcription.