Emily Dickinson Lexicon

BIT, n.¹ [Sax. bitol, gebæte, gebætel, a bit; bætan, to bit or curb.]

The iron part of a bridle which is inserted in the mouth of a horse, and its appendages, to which the reins are fastened. It includes the bit mouth, the branches, the curb, the sevel holes, the tranchefil and cross chains. Bits are of various kinds, as the musrole, snaffle, or watering bit; the canon mouth, jointed in the middle; the canon or fast mouth, all of a piece, kneed in the middle; the scatch-mouth; the masticador, or slavering bit, &c. – Johnson. Encyc.