stealthiness vs undercover

stealthiness

noun
  • The property of being stealthy. 

undercover

noun
  • A person who works undercover. 

verb
  • To provide too little coverage. 

adj
  • Performed or happening in secret. 

  • Employed or engaged in spying or secret investigation. 

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