chimera vs fanciful notion

chimera

noun
  • An organism with genetically distinct cells originating from two or more zygotes. 

  • Any fantastic creature combining parts from different animals. 

  • Synonym of bogeyman: any terrifying thing, especially as an unreal, imagined threat. 

  • Anything composed of very disparate parts. 

  • A grotesque like a gargoyle, but without a spout for rainwater. 

  • A foolish, incongruous, or vain thought or product of the imagination. 

fanciful notion

How often have the words chimera and fanciful notion occurred in a corpus of books? (source: Google Ngram Viewer )