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negative hallucination

British  

noun

  1. psychol an apparent abnormal inability to perceive an object

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Example Sentences

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Or he may perceive them, be unable to explain them, and feel considerable terror until the "negative hallucination" is dissolved by a fresh word of command.

From Project Gutenberg