gratuitous vs skippable

gratuitous

adj
  • Given freely; unearned. 

  • Unjustified or unnecessary; not called for by the circumstances. 

skippable

adj
  • Capable of being skipped. 

  • Not worth watching or doing; missable. 

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