primal vs trigger

primal

verb
  • To take part in primal therapy. 

adj
  • Being the first in time or in history. 

  • Of greatest importance; primary. 

  • Being one of the pieces of meat initially separated from the carcass during butchering, prior to division into smaller cuts. 

noun
  • A primal cut (of meat). 

trigger

verb
  • To initiate something. 

  • To fire a weapon. 

  • To spark a response, especially a negative emotional response, in (someone). 

  • To activate; to become active. 

noun
  • An electronic transducer allowing a drum, cymbal, etc. to control an electronic drum unit or similar device. 

  • An event, experience or other stimulus that initiates a traumatic memory or a strong reaction in a person. 

  • An SQL procedure that may be initiated when a record is inserted, updated or deleted; typically used to maintain referential integrity. 

  • A concept or image that upsets somebody by sparking a negative emotional response. 

  • A similar device used to activate any mechanism. 

  • An event that initiates others, or incites a response. 

  • A pulse in an electronic circuit that initiates some component. 

  • A text string that, when received by a player, will cause the player to execute a certain command. 

  • A device that manually lengthens (or sometimes shortens) the slide or tubing of a brass instrument, allowing the pitch range to be altered while playing. 

  • A finger-operated lever used to fire a gun. 

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