What does the word delusion mean?

Usage examples for delusion

  1. This set me thinking about the extent of his madness, or to speak more mildly and more correctly, of his delusion. – The Queen of Hearts by Wilkie Collins Last Updated: January 3, 2009
  2. The poor man is under a strong mental delusion, he cannot act in the least; however, we shall see what he will do with " Venice Preserved." – Records of a Girlhood by Frances Ann Kemble
  3. Unless he is living under the power of some strong delusion, he knows that he is not worthy of regard. – The True Citizen, How To Become One by W. F. Markwick, D. D. and W. A. Smith, A. B.