interrupter

noun

1. One who or that which interrupts.

   “The interrupter bowed, smiled, stroked his beard, and relapsed into his chair.”

2. A device for opening and closing an electrical circuit.
3. (humorous, slang)An interpreter (person who interprets speech in a foreign language).

   “The other half of the local staff was employed as interpreters, often affectionately known as 'interrupters.'”

   “The Coldstream Guards were already in place and knocked on the door. Daz Farrugia stood at the door with the Iraqi interrupter. […] The door opened and a middle aged Iraqi man stood there in his pajamas, gobbing off in Arabic, saying who knows what, but I guessed it was not very complimentary; the interpreter managed to calm him down.”