death sentence vs manslaughter

death sentence

noun
  • A decree that someone be put to death as a punishment for a crime; a sentence of execution. 

  • Anything that spells death. 

manslaughter

noun
  • The unlawful killing of a human, either in negligence or incidentally to the commission of some unlawful act, but without specific malice, or upon a sudden excitement of anger; considered less culpable than murder, but more culpable than justifiable homicide. 

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