A piece of armour for the head; a head-piece, a casque; also, a piece of armour for the head of a horse; a kind of mask or visor with holes for…

Apparently a corruption of chaufron, shawfron, chamfron, n.; perhaps confused with the heraldic chevron, n.1

The frontlet of a barded or armed horse.

The frontlet of a barded horse: = chaffron, n.0, chamfron, n.

A piece of plate armour covering the forehead of a horse; = chamfron, n. archaic and historical in later use.

Another form of chamfron (chamfrain, n.)

Something applied to the forehead. Obsolete. A piece of defensive armour for a horse's head; = front-stall n. (Cf. French frontail, fronteau.)

Apparently a corruption of chaffron, n., chamfron, n.: cf. cheveronne, n. in same sense.

Something worn on the forehead. = frontal, n. 1b, front-stall (see front, n. compounds 2).

an appendage to the bridle covering the horse's forehead.