Definitions
1.nounLarge capital warship displacing tens of thousands of tons, heavily armoured and armed with big guns. Battleships are now obsolescent, replaced by smaller vessels with guided missiles. Types: dreadnought, pre-dreadnought.
2.nounNon-functional rocket stage, used for configuration and integration tests.
3.nounA guessing game played on grid paper, see Battleship (game)