What does the word aberration mean?

Usage examples for aberration

  1. It is gratifying to one who would above all things avoid the insanity of fancying himself a more momentous or touching object than he really is, to find that nobody expects from him the least sign of such mental aberration, and that he is evidently held capable of listening to all kinds of personal outpouring without the least disposition to become communicative in the same way. – Impressions of Theophrastus Such by George Eliot
  2. You must know that he has, for some months, had periods of temporary aberration, and that all his delusions have been of a sanguinary nature. – The-Darrow-Enigma by Severy, Melvin Linwood