to rain heavily; or, for a cloth to become thick and tightly packed (see Molina)
Orthographic Variants:
tilaua
Alonso de Molina:
tilaua. (pret. otilauac.) llouer reziamente o hazerse gruessa la manta y tupirse. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 113r. col. 1. Thanks to Joe Campbell for providing the transcription.