potro.

(a loanword from Spanish)

Headword: 
potro.
Principal English Translation: 

a colt; a young horse; or a device made of wood to detain horses when they are being doctored
(a loanword from Spanish)

Attestations from sources in English: 

macehualtin quinahuatia quimachtia ypotros amo tlaxtlahua = he orders the commoners to break his colts and he does not pay for it (Jalostotitlan, Jalisco, 1611)
Beyond the Codices, eds. Arthur J.O. Anderson, Frances Berdan, and James Lockhart (Los Angeles: UCLA Latin American Center, 1976), Doc. 27, 172–173.

Attestations from sources in Spanish: 

ze burro huel yxtlamatini yhuan cenpoali onchicome potros yhuan nahui mulitas yhuan caxtoli machos ye ce xihuitl quipia = Y un burro maestro y veinti y ocho potros con cuatro mulitas, y quince machos de año (Tepexi de la Seda, 1621)
Vidas y bienes olvidados: Testamentos en náhuatl y castellano del siglo XVII, vol. 3, Teresa Rojas Rabiela, et al, eds. (México: CIESAS, 2002), 112–113.