E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Buffer (A).
A chap. The French bouffer (older form, bauffer) meant to eat, as il bauffera tout seul. If this is the basis of the word, a buffer is one who eats with us, called a Commoner in our universities.
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I always said the old buffer would.Miss Braddon: Lady Audleys Secret.