clutch vs commutator

clutch

noun
  • A device to interrupt power transmission, commonly used to separate the engine and gearbox in a car. 

  • The claw of a predatory animal or bird. 

  • An important or critical situation. 

  • A brood of chickens or a sitting of eggs. 

  • A fastener that attaches to the back of a tack pin to secure an accessory to clothing. (See Clutch (pin fastener).) 

  • A small handbag or purse with no straps or handle. 

  • A group or bunch (of people or things). 

  • Any device for gripping an object, as at the end of a chain or tackle. 

  • A grip, especially one seen as rapacious or evil. 

  • The pedal in a car that disengages power and torque transmission from the engine (through the drivetrain) to the drive wheels. 

  • A difficult maneuver 

adj
  • Performing or tending to perform well in difficult, high-pressure situations. 

verb
  • To unexpectedly or luckily succeed in a difficult activity. 

  • To hatch. 

  • To seize, as though with claws. 

  • To grip or grasp tightly. 

  • To win in a 1vX (one versus X) situation. 

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. 

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