onxiuhtia cahuallo.

(a loanword from Spanish)

Headword: 
onxiuhtia cahuallo.
Principal English Translation: 

a two-year-old colt (see Molina)
(partly a Spanish loanword, caballo, horse)

Orthographic Variants: 
onxiuhtia cauallo
Alonso de Molina: 

onxiuhtia cauallo. potro de dos años. et sic de alijs.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 77v. col. 1. Thanks to Joe Campbell for providing the transcription.