pocket battleship

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Any of several German warships built in the late 1920s and early 1930s that were smaller, less well armed, and less heavily armored than a conventional battleship.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun nautical Any of a class of German cruisers, having guns normally found on a battleship, operated during World War II; a battlecruiser

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a small battleship built to conform with treaty limitations on tonnage and armament (from 1925 to 1930)