Definitions

1. noun

a piece of fabric or other material that covers the lower part of a helmet or a mail coif, typically hanging down in front

“The medieval knight wore an aventail under his helmet to protect his face and neck from sword blows.”

2. noun

a hanging strip of fabric at the front of a hood or cowl

“The monk’s hood had a decorative aventail that framed his face.”

3. noun

a decorative piece of fabric or other material attached to the front of a helmet or hood

“The knight’s helmet had an aventail with intricate embroidery and gemstones.”