embryo vs kick-off

embryo

noun
  • The beginning; the first stage of anything. 

  • A rudimentary plant contained in the seed. 

  • In the reproductive cycle, the stage after the fertilization of the egg that precedes the development into a fetus. 

  • In viviparous animals, the young animal's earliest stages in the mother's body 

  • In humans, usually the cell growth up to the end of the seventh week in the mother's body 

  • An organism in the earlier stages of development before it emerges from the egg, or before metamorphosis. 

kick-off

noun
  • The opening sequence of any event. 

  • The opening kick of each half of a game of football. 

  • The opening sequence of notes in a song, usually played by the song's main instrument, to indicate the beginning of the song. 

How often have the words embryo and kick-off occurred in a corpus of books? (source: Google Ngram Viewer )