commutator vs disconnect

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. 

disconnect

noun
  • A switch used to isolate a portion of an electrical circuit. 

  • A lack of connection or accord; a mismatch. 

  • The deliberate severing of ties with family, friends, etc. considered antagonistic towards Scientology. 

  • A break or interruption in an existing connection, continuum, or process; disconnection. 

verb
  • To sever or interrupt a connection. 

  • To remove the connection between an appliance and an electrical power source. 

  • Of a person, to become detached or withdrawn. 

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