life preserver vs preserver

life preserver

noun
  • A buoyant ring or vest intended to keep a person afloat. 

preserver

noun
  • A life preserver. 

  • A person who prepares preserves of fruit or preserved meats. 

  • A person who refinishes furniture. 

  • One who preserves. 

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