ittoni. cosa visible. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 43r. col. 2. Thanks to Joe Campbell for providing the transcription.
Frances Karttunen:
(I)TTŌNI something that can be seen / cosa visible (M) [(4)Zp. 125, 176]. See (I)TTA. Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 108.