A person is said to be non-committal when he neither assents nor dissents.

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1841.  Mr. Walker of Mississippi said Mr. Clay was so much ashamed of the Bank bill, that he declared he must remain non-committal. Mr. Clay. No such thing. Mr. Walker. You said you were non-committal.—U.S. Senate, Aug. 30: Cong. Globe, p. 404.

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1845.  We have had bold messages from the land of abstractions (Virginia); this is a message from the headquarters of non-committalism.—Mr. J. P. Kennedy of Maryland, House of Repr., Jan. 11: id., p. 295, App.

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1851.  A successful politician here [in New York] is either … a blind partisan, who known nothing outside of ‘the regular ticket,’ or a ‘non-committal’ man, who says everything to everybody, and never gave an intelligible, manly, straightforward opinion in his life.—Fraser’s Mag., xliv. p. 287/2 (Sept.). (N.E.D.)

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1885.  “She ’s a pretty girl,” said Corey non-committally. “But I suppose a great many pretty girls have to earn their living.”—W. D. Howells, ‘The Rise of Silas Lapham,’ chap. viii.

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