concealment vs indication

concealment

noun
  • The practice of keeping secrets. 

  • protection from observation or surveillance. 

  • The condition of being hidden or concealed. 

indication

noun
  • Any symptom or occurrence in a disease, which serves to direct to suitable remedies. 

  • That which serves to indicate or point out; mark; token; sign; symptom; evidence. 

  • Act of pointing out or indicating. 

  • Discovery made; information. 

  • An declared approximation of the price at which a traded security is likely to commence trading. 

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