A deciduous tree with distinctive deeply lobed leaves, acorns, and notably strong wood, typically of England and northeastern North America, included in genus Quercus.
It was not far from the house; but the ground sank into a depression there, and the ridge of it behind shut out everything except just the roof of the tallest hayrick. As one sat on the sward behind the elm, with the back turned on the rick and nothing in front but the tall elms and the oaks in the other hedge, it was quite easy to fancy it the verge of the prairie with the backwoods close by.1879, R[ichard] J[efferies], chapter 1, in The Amateur Poacher, London: Smith, Elder, & Co., […], →OCLC:
Instead there were the white of aspens, streaks of branch and slender trunk glistening from the green of leaves, and the darker green of oaks, and through the middle of this forest, from wall to wall, ran a winding line of brilliant green which marked the course of cottonwoods and willows.1912 January, Zane Grey, chapter 8, in Riders of the Purple Sage […], New York, N.Y.; London: Harper & Brothers Publishers, →OCLC:
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The wood of the oak.
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A rich brown color, like that of oak wood.
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Any tree of the genus Quercus, in family Fagaceae.
› Any tree of other genera and species of…
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The she-oaks in Allocasuarina and Casuarina, of family Casuarinaceae
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Lagunaria, white oak, in family Malvaceae
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Various species called silky oak, in family Proteaceae
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Toxicodendron, poison oak, in family Anacardiaceae
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Various tanbark oak or stone oak species in family Fagaceae, genera Lithocarpus and Notholithocarpus.
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The outer (lockable) door of a set of rooms in a college or similar institution. (Often in the phrase sport one's oak.)
[E]very set of rooms has two doors, and I soon learned that the outer door, which is thick and solid, is called the oak, and to shut it is termed, to sport.1833, Thomas Jefferson Hogg, chapter 2, in Shelley at Oxford, London: Methuen:
It was hardly the thing for a master to sport his oak where another member of the staff was concerned.1930, Frank Richards, The Magnet: Prout's Lovely Black Eye:
1 more example
The vesper bell had rung its parting note; the domini were mostly caged in comfortable quarters, discussing the merits of old port; and the merry student had closed his oak, to consecrate the night to friendship, sack, and claret.The New Sporting Magazine (volume 15, page 23)