A person is said to be non-committal when he neither assents nor dissents.
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.
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.
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.Frasers Mag., xliv. p. 287/2 (Sept.). (N.E.D.)
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.