at peace vs peaceful

at peace

prep

  • Free of worries; peaceful. 

  • Dead. 

peaceful

adj

  • Motionless and calm. 

  • Inclined to peace. 

  • Not at war; not disturbed by strife or turmoil. 

noun

  • a Muslim; especially a violent member of a radical Islamist group. 

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