AVENTAIL, or Avantaille (O. Fr. esventail, presumably from a Latin word exventaculum, air-hole), the mouthpiece of an old-fashioned helmet, movable to admit the air.
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AVENTAIL, or Avantaille (O. Fr. esventail, presumably from a Latin word exventaculum, air-hole), the mouthpiece of an old-fashioned helmet, movable to admit the air.