A gum tree, or its trunk when cut down.

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1817.  Any portion so cut off is called a gum, a name probably arising from the almost exclusive application of the gum tree to these purposes.—J. Bradbury, ‘Travels in America,’ p. 286 n. (N.E.D.)

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1836.  A chap just about as rough hewn as if he had been cut out of a gum log with a broad axe, and sent into the market without even being smoothed off with a jack plane.—‘Col. Crockett in Texas,’ pp. 81–2 (Phila.).

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1836.  I’m shaggy as a bear, wolfish about the head, active as a cougar, and can grin like a hyena, until the bark will curl off a gum log.Id., p. 186.

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1845.  I then got in among the bushes, and made a thorough change in my dress, taking care to hide the old clothes in the hollow of a gum.—W. G. Simms, ‘The Wigwam and the Cabin,’ p. 103 (Lond.).

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