onset vs sortie

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. 

sortie

noun
  • An act of trying to enter a new field of activity. 

  • An operational flight carried out by a spacecraft involving a return to Earth. 

  • An operational flight carried out by a single military aircraft. 

  • An act of venturing out to do a task, etc. 

  • An attack made by troops from a besieged position; a sally. 

  • An attacking move. 

  • Synonym of sally port (“an entry to or opening into a fortification to enable a sally”) 

  • A series of aerial photographs taken during the flight of an aircraft; (by extension) a photography session. 

verb
  • To carry out a sortie; to sally. 

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