Definition of "bever"

Wherefore King Ban and King Bors made them ready, and dressed their shields and harness, and they were so courageous that many knights shook and bevered for eagerness.

1485, Sir Thomas Malory, Le Morte D'Arthur, page 25

And, passing forward with furious affret, / Pierst through his bever and quite into his brow.

1590, Edmund Spenser, The Faerie Queene

He who lookes you in the face, ſaith he ſees you, though the reſt of your bodie be within your cloathes, and if you, being an ὁωλομάχος a cataphract in your proteſtantiſh πανοπλία [panoplía, suit of armour] should for fear pull downe your beuer before you come into the liſt, your Aduerſarie for all that might light vpon your ( ) vnleſſe you bring with you Giges his ring, ſo to make your ſelf inuiſible; [...]

1635, L. I. [pseudonym; John Lechmere], “The Third Argument was about the Killing Letter; out of Origen, […]”, in The Relection of a Conference Tovching the Reall Presence. Or A Bachelovrs Censvre of a Masters Apologie for Doctour Featlie, Douai: Lavrence Kellam, page 333

Some close helmets have a farther improvement called a bever, the bever when closed covers the mouth and chin, and either lifts up by revolving on the same pivots as the visor, or lets down by means of two or more pivots on each side near the jaws, in which case the bever consists of several laminæ or plates, one shutting over the other.

1786, Francis Grose, A Treatise on Ancient Armour and Weapons, page 8

Bid my subsiser carry my hackney to the buttery, and give him his bever; it is a civil and sober beast, and will drink moderately.

1625, John Fletcher, Philip Massinger, “The Elder Brother. A Comedy.”, in Comedies and Tragedies […], London: […] Humphrey Robinson, […], and for Humphrey Moseley […], published 1679, (please specify the act number in uppercase Roman numerals, and the scene number in lowercase Roman numerals)

It seemeth that wee daily shorten the use of this, and that in our houses (as I have seene in mine infancie) breakfasts, nunchions, and beavers [translating collations] should be more frequent and often used than now adayes they are.

1603, Michel de Montaigne, chapter 2, in John Florio, transl., The Essayes […], book II, London: […] Val[entine] Simmes for Edward Blount […]

Thirty meals a day and ten bevers.

1604, Christopher Marlowe, Dr. Faustus

Very softly I boiled water, made a sandwich from the remains of the luncheon roast chicken, scalded the Twining creature. Then I softly carried my bever to the study on a tray […].

1980, Anthony Burgess, Earthly Powers