noun, masculine/fʁɛ̃/plural: freins
bit (equipment put in a horse's mouth); brake (of a vehicle, etc.); restraint, reserve; frenulum
“frein de la langue” — frenulum linguae
Synonyms: mors, filet
Inherited from Old French frein, from Latin frēnum n. Cognate with Portuguese freio and Spanish freno. Cf. the borrowed freiner.