launch vs onset

launch

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

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

  • 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. 

onset

noun
  • A setting about; a beginning. 

  • The initial portion of a syllable, preceding the syllable nucleus. 

  • The beginning of a musical note or other sound, in which the amplitude rises from zero to an initial peak. 

  • The initial phase of a disease or condition, in which symptoms first become apparent. 

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