Forms: 4–9 aventail(e, -ayle, 4–5 aventaille, -ale, avantaille, adventayle. [a. AF. *aventail = OF. esventail air-hole, f. esventer (see prec.): the Lat. type is *exventaculum (cf. prōpugnāculum). For the form in adv-, see AD- pref. 2.]
The movable front or mouthpiece of a helmet, which may be raised to admit fresh air.
c. 1340. Gaw. & Gr. Knt., 603. Wyth a lyȝtli vrysoun ouer þe auentayle.
c. 1374. Chaucer, Troylus, V. 1558. As he drough a kynge by th’ avantaille.
a. 1400. Octouian, 1153. Hys adventayle he gan unlace.
1460. Lybeaus Disc., 1618. Pysane, aventayle, and gorgere.
1805. Scott, Last Minstrel, II. iii. And lifted his barred aventayle.
1842. Blackw. Mag., LII. 17. With pierced aventails for the eyes and mouth.
