something done by a "noble and magnificent" lord or ruler (see Molina)
Orthographic Variants:
tlahtoca tlachiuhtli
Alonso de Molina:
tlatoca tlachiuhtli. hecho de persona noble ymagnifica. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 140v. col. 2. Thanks to Joe Campbell for providing the transcription.