to be a person who speaks for others, helping them (see Molina)
IPAspelling:
tɬɑhtɑlwiɑː
Alonso de Molina:
tlatalhuia. nite. (pret. onitetlatalhui.) ser procurador de otros, o hablar por ellos, fauoreciendolos y ayudandolos. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 134v. col. 1. Thanks to Joe Campbell for providing the transcription.
Frances Karttunen:
TLAHTALHUIĀ vt to speak in behalf of someone; to malign someone / ser procurador de otros o hablar por ellos, favoreciendolos y ayudandolos (M), lo ultraja, lo insulta (Z) [(1)Bf.5v,(1)Cf.65r,(3)Zp.72,126,196]. M and Z have contradictory senses, but both are derivable from the literal sense of IHTALHUIĀ, as the applicative form of (I)HTOĀ. Z omits the glottal stop. See IHTALHUIĀ. Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 262.