The movable front or mouthpiece of a helmet, which may be raised to admit fresh air.

The lower movable part of the front of a helmet, as distinct from the vizor; latterly, the whole movable part including the vizor.

= ventail, n. 2.

an addition to the front of a helmet as a protection for the face, used especially in tournaments. Obsolete.

In ancient armour, a chin piece pierced with breathing-holes, worn with the burgonet.

= volant piece n. at sense A. 2 (see sense A. 2 above). rare.