The one on the far side; the one of less use.

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1807.  We behold a clumsy, awkward off ox trying the tricks of a kitten.—The Balance, Aug. 25, p. 267: from the N.Y. Evening Post.

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1827.  A pair of oxen now grown so much alike that no one can tell which is the off ox.Mass. Spy, July 25.

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1848.  

        Ez to the answerin’ o’ questions,
I ’m an off ox at bein druv.
Lowell, ‘Biglow Papers,’ No. 7.    

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1862.  Trying to make a nigger act like a white man is jest like old Sol Hopkins, one year harnessing his off ox an his hoss together to plow corn.—Seba Smith, ‘Letters of Major Jack Downing,’ April 29.

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