(A). A snap before dinner, which damps or takes off the edge, of appetite. “That's a damper” also means a wet-blanket influence, a rebuff which damps or cools one's courage.
Also a large thin cake of flour and water baked in hot ashes. The mute of a stringed instrument to deaden the sound is also called a “damper.”
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894
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