for the head to feel faint, or hurt or ache a lot (see Molina)
Orthographic Variants:
quaiuinti, quaihuinti
Alonso de Molina:
quaiuinti. ni. (pret. oniquaiuintic.) desuanecerseme lacabeza, o dolerme mucho. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 84r. col. 2. Thanks to Joe Campbell for providing the transcription.