ventail, ventaile, ventayle

[O. Fr. ventaille, from vent (Latin vent us ) =wind.] The lower movable part of the front of the helmet, which admitted air for breathing, the upper 1. The same as VENT (1), s., 4. (1). 2. A vent or outlet for air or gases. "For, the town and temple, as we observed, were seated on a bare and hollow rock; which would here and there afford vent - holes for such fumes as generated within to transpire."-War burton: Julian , bk. ii., ch. vi.