undeceive

• undeceave (obsolete)

un- +‎ deceive

undeceive (third-person singular simple present undeceives, present participle undeceiving, simple past and past participle undeceived)

1. (transitive) To free from misconception, deception or error.
   • 1690, Robert Boyle, “A Previous Hydrostatical Way of Estimating Ores” in Medicina Hydrostatica, London: Samuel Smith, Section V, p. 168,

     […] Marcasites, I say, being thus fitted to delude the unskilful, I have had much ado to undeceive some, that brought or sent me them from America, of the pleasing Confidence they had entertained, that these promising Fossiles were Lumps of rich Ore of Gold, or Silver.

   • 1782, Frances Burney, Cecilia, London: T. Payne & Son and T. Cadell, Volume 3, Book 6, Chapter 9, p. 318,

     Undeceived in her expectations and chilled in her hopes, the heart of Cecilia no longer struggled to sustain its dignity, or conceal its tenderness […]

   • 1863, Louisa May Alcott, Pauline’s Passion and Punishment, Frank Leslie’s Illustrated Newspaper, Volume XV, Number 379, 3 January, 1863, Chapter 1, p. 229,

     If you think that this loss has broken my heart undeceive yourself, for such as I live years in an hour and show no sign.

   • 1918, Booth Tarkington, The Magnificent Ambersons, New York: Doubleday, Page & Co., Chapter 33, p. 467,

     Early every morning she made something she called (and believed to be) coffee for George, and he was gallant enough not to undeceive her.

• disabuse

• undeceiver

• undeceive in Webster’s Revised Unabridged Dictionary, G. & C. Merriam, 1913.