freno.

(a loanword from Spanish)

Headword: 
freno.
Principal English Translation: 

reins on a horse or bridle (see attestations)

Attestations from sources in English: 

nicpia se silla yca freno espuelas = I have a saddle with its bridle and spurs (Saltillo, 1682)
Leslie S. Offutt, "Levels of Acculturation in Northeastern New Spain; San Esteban Testaments of the Seventeenth and Eighteenth Centuries," Estudios de cultura náhuatl 22 (1992), 409–443, see page 434–435.

silla xinete yca coxinillo sin estribus yhuan Almardiga mopiya sin freno (S. Francisco Analcotitlan [Jalisco?], 1652)
Beyond the Codices, eds. Arthur J.O. Anderson, Frances Berdan, and James Lockhart (Los Angeles: UCLA Latin American Center, 1976), Doc. 8.

Attestations from sources in Spanish: 

ce mula [tlil]tic de cilla yca mochi freno espuelas = tengo una mula prieta de silla con todo su ajuar, espuelas, etcétera (Cuautitlan, Tepozotlan, 1639)
Vidas y bienes olvidados: Testamentos en náhuatl y castellano del siglo XVII, vol. 3, Teresa Rojas Rabiela, et al, eds. (México: CIESAS, 2002), 212–213.