- n a cell in which soldiers who are prisoners are confined
- n a room used by soldiers on guard
- A whole regiment obeyed, and Louis (no soldier) marched them stoutly into a blind alley; immediately, loyal officers put the pint-sized pretender in the guardroom.
- He went AWOL at Christmas time, he said, because a guardroom sergeant made his life miserable.
- They killed the sentry outside, burst into the guardroom, shot three more policemen, then tossed homemade bombs into the depot's gas tanks.