grave vs suicidal

grave

noun
  • Deceased people; the dead. 

  • Death, destruction. 

  • Any place of interment; a tomb; a sepulcher. 

  • An excavation in the earth as a place of burial 

  • A written accent used in French, Italian, and other languages. è is an e with a grave accent (`). 

  • A count, prefect, or person holding office. 

adj
  • Serious, in a negative sense; important, formidable. 

  • Low in pitch, tone etc. 

  • Characterised by a dignified sense of seriousness; not cheerful. 

suicidal

noun
  • Someone suicidal; someone likely to kill themselves. 

adj
  • Likely to commit, or to attempt to commit, suicide. 

  • Extremely reckless. 

  • Highly likely to certain to result in the deaths of the participants; dangerous or reckless to such a degree as to be tantamount to suicide for those taking part. 

  • Pertaining to suicide. 

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