certifiably vs substantially

certifiably

adv
  • To a great extent. 

  • With the potential for certification. 

  • Undoubtedly, demonstrably. 

  • Genuinely 

substantially

adv
  • To a great extent; in essence; essentially. 

  • Without material qualifications. 

  • In a strong substantial manner; considerably. 

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