to say something clearly and correctly; or, to clarify that which is difficult to understand (see Molina)
Orthographic Variants:
melauacaytoa, melahuacaytoa
Alonso de Molina:
melauacaytoa. nic. (pret. onicmelauacaito) dezir clara y derechamente la cosa, o declarar lo que esta escuro de entender. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 55r. col. 2. Thanks to Joe Campbell for providing the transcription.