to celebrate a festivity or holiday (see Molina)
ilhuichiua. n. (pret. onilhuichiuh.) celebrar fiesta. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 37v. col. 1. Thanks to Joe Campbell for providing the transcription.