To shake.

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1833.  Mind how ye jounce that air chist about! Have to pay for all ye break o’ mine, I tell ye now!—John Neal, ‘The Down-Easters,’ i. 14.

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1838.  I want nothing but to get out of this tarnation basket. I calculate that my heft will be too much for it. Every time it knocks agin the house it jounces my life out.—Caroline Gilman, ‘Recollections of a Southern Matron,’ p. 43 (N.Y.).

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a. 1854.  If man causes everything, down here to hobble, hitch, grate, jerk, jounce and joggle along, up thar all glides on as “slick” as goose-grease; and silently as “a snail slips over a cabbage leaf on a dewy morning.”—Dow, Jun., ‘Patent Sermons,’ iv. 70.

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1910.  Nearer shore is a longer, narrower raft, supported by two cigar-shaped wind-bags looking like smaller editions of the Zeppelin airship. A favorite diversion is to rock this raft violently from side to side till most of the occupants slide off. Last Sunday the raft was jounced about so severely that it broke its anchorages.—N.Y. Ev. Post, Aug. 4.

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