"Frig" is known in the U.S., too, but is usually taken to be a minced form of "fuck" rather than a special slang word for masturbate as it is in the U.K. Hence (obFolk) the line "Frigging in the rigging" that occurs in some versions of the chorus of "The Good Ship Venus" calls up, on this side of the Atlantic, a preposterously acrobatic image.

My wisecrack about "Nazi" was based on the fact that it is a shortening of "Nationalsozialist". Outside the context "tion", the "t" does not suggest the pronunciation "ts", so it got changed to "z" which does. My understanding is that Mr Churchill's English spelling pronunciation agreed with common British usage of his day. In the U.S. we always imitated the German pronunciation.