noun
More fully "overcup oak". Either of two North American oaks in which the acorn is almost completely enclosed by the cup or its scales: (a) the mossy-cup oak, Quercus macrocarpa (also "overcup white oak"); (b) the swamp white oak, Q. lyrata, of the southern U.S.
Origin
Early 19th century; earliest use found in Frederick Pursh (1774–1820). From over- + cup.
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