shallow vs substantial

shallow

adj
  • Not intellectually deep; not penetrating deeply; simple; not wise or knowing. 

  • Not steep; close to horizontal. 

  • Not far forward, close to the net. 

  • Having little depth; significantly less deep than wide. 

  • Concerned mainly with superficial matters. 

  • Extending not far downward. 

  • Lacking interest or substance. 

noun
  • A costermonger's barrow. 

  • A shallow portion of an otherwise deep body of water. 

  • A fish, the rudd. 

verb
  • To make or become less deep. 

substantial

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

  • Most important; essential. 

  • 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. 

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

noun
  • Anything having substance; an essential part. 

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