blue-pencil v. t. To change, delete, or abridge (a portion of a text) with a blue pencil (or as if with a blue pencil), as in the editing process; of books, etc.
... but when the dignity of his official position is threatened he can be serious enough. When he was charge d'affaires in Havana a young Cuban journalist assaulted him. That journalist is still in jail. In Brussels a German officer tried to blue-pencil a cable Gibson was sending to the State Department. Those who witnessed the incident say it was like a buzz-saw ... — With the Allies • Richard Harding Davis