myriad vs untold

myriad

adj
  • Great in number; innumerable, multitudinous 

  • Multifaceted, having innumerable elements 

noun
  • A countless number or multitude (of specified things) 

  • Ten thousand; 10,000 

untold

adj
  • Not able to be counted, measured, told, expressed in words, or described; extremely large in scale, number, quantity, suffering, damage, etc.; uncountable, unmeasurable, immeasurable, indescribable, inexpressible. 

  • Not told; not related; not revealed; secret. 

  • Not numbered or counted. 

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