mild vs substantial

mild

adj
  • Not sharp or bitter; not strong in flavor. 

  • Of only moderate severity; not strict. 

  • Not serious or dangerous. 

  • Moderately warm, especially less cold than expected. 

  • Gentle and not easily angered. 

  • Not overly felt or seriously intended. 

  • Acting gently and without causing harm. 

noun
  • A relatively low-gravity beer, often with a dark colour; mild ale 

substantial

adj
  • Having good substance; strong; stout; solid; firm. 

  • Most important; essential. 

  • Not imaginary; real; actual; true; veritable. 

  • Having a substance; actually existing. 

  • Corporeal; material; firm. 

  • Possessed of goods or an estate; moderately wealthy. 

  • Satisfying; having sufficient substance to be nourishing or filling. 

  • Large in size, quantity, or value; ample; significant. 

noun
  • Anything having substance; an essential part. 

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