To propel a boat by laying hold of bushes and overhanging branches, and walking toward the stern.

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1826.  We began to pull the boat up the stream, by a process, which, in the technics of the boatmen, is called “bush-whacking.”—T. Flint, ‘Recollections,’ p. 86.

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1854.  When the waters are high, and the boat can run along under bushes on the river-bank, pulling up by the bushes, this is called “bush-whacking.”—Lambert Lilly, ‘History of the Western States,’ p. 30 (Boston).

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