aventail

• aventaile

From Middle English aventayle, from Old French esventail (“air-hole”), from esventer (Modern French éventer), from Latin ex (“out”) + ventus (“wind”).

aventail (plural aventails)

1. (chain mail armour) the flap or adjustable part of the hood of mail, which when unfastened allowed the hood to drop upon the shoulders.
2. (solid armour) The movable front to a helmet; the ventail.

• aventail in Webster’s Revised Unabridged Dictionary, G. & C. Merriam, 1913.
• The Century Dictionary, The Century Co., New York, 1914

• alvanite, valentia, vanalite