fantastical vs imaginary

fantastical

adj
  • Of or pertaining to fantasy. 

  • Fantastic. 

  • Fanciful or whimsical. 

imaginary

adj
  • Existing only in the imagination. 

  • Having no real part; that part of a complex number which is a multiple of √ (called imaginary unit). 

noun
  • The set of values, institutions, laws, and symbols common to a particular social group and the corresponding society through which people imagine their social whole. 

  • Imagination; fancy. 

  • An imaginary quantity. 

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