launch vs lifeline

launch

noun
  • A boat used to convey guests to and from a yacht. 

  • The act or fact of launching (a ship/vessel, a project, a new book, etc.). 

  • An open boat of any size powered by steam, petrol, electricity, etc. 

  • The boat of the largest size and/or of most importance belonging to a ship of war, and often called the "captain's boat" or "captain's launch". 

  • The movement of a vessel from land into the water; especially, the sliding on ways from the stocks on which it is built. (Compare: to splash a ship.) 

  • An event held to celebrate the launch of a ship/vessel, project, a new book, etc.; a launch party. 

verb
  • To cause (a vessel) to move or slide from the land or a larger vessel into the water; to set afloat. 

  • To cause (a rocket, balloon, etc., or the payload thereof) to begin its flight upward from the ground. 

  • To throw (a projectile such as a lance, dart or ball); to hurl; to propel with force. 

  • Of a ship, rocket, balloon, etc.: to depart on a voyage; to take off. 

  • To send out; to start (someone) on a mission or project; to give a start to (something); to put in operation 

  • To start to operate. 

  • To move with force and swiftness like a sliding from the stocks into the water; to plunge; to begin. 

  • To release; to put onto the market for sale 

  • To start (a program or feature); to execute or bring into operation. 

lifeline

noun
  • On the deck of a boat, a line to which one can attach oneself to stay aboard on rough seas. 

  • A particular crease in the palm. 

  • A line from the diver to a tender at the surface control point. 

  • A line to which a drowning or falling victim may cling. 

  • A means or route for transporting indispensable supplies. 

  • System or structure of vital importance to a community. 

  • A source of salvation in a crisis. 

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