commutator vs trigger

commutator

noun
  • An electrical switch, in a generator or motor, that periodically reverses the direction of an electric current. 

  • A binary map in a given group G, given by [g, h] = ghg⁻¹h⁻¹, where g and h are elements of G, which yields the group's identity if and only if the group operation commutes for g and h. 

  • A binary map in a given ring R, given by [a, b] = ab − ba, where a and b are elements of R, which yields the ring's zero element if and only if the multiplication operation commutes for a and b. 

trigger

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

  • 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 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. 

verb
  • To fire a weapon. 

  • To initiate something. 

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

  • To activate; to become active. 

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