zan iyuhca.

Headword: 
zan iyuhca.
Principal English Translation: 

by themselves; or, apart, separate; or, to him alone

Orthographic Variants: 
zaniyuca, zan iyuca, zan iyuhca, çan iyuca, çaniyuhca
Alonso de Molina: 

zaniyuca. a solas, o aparte, o a el solo. (aduerbio.)
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 14r. col. 2. Thanks to Joe Campbell for providing the transcription.