A term used in history to reference the deliberately obfuscating collection of terms that Nazi's directly involved with the Final Solution were taught to use. (i.e. "final solution" "relocation")
The purpose of this protocol was to allow for a more efficient and expedient extermination operation by allowing those directly involved a sort of blissful ignorance towards their actions.
For further reading see: Eichmann in Jerusalem By Hannah Arendt.