Definition of "two-decker" [two•-deck•er]

• A sail warship, which carried her guns on two fully-armed decks. Usually additional guns were carried on the upper works (forecastle and quarterdeck) but this was not a continuous battery so were not counted. Two-deckers ranged all the way from the small 40-gun fourth-rate up to 80- or even 90-gun ships, with the third-rate or "seventy-four" being the archetype. (noun)

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• "We were "lucky" enough to join a group on the two-decker boat called the Lucky Lady."
• "But the hull of the ship is a recycled bone carving of a three-masted, two-decker warship mounting 66 guns."
• "Soon the Canadian informed me that she was a large, armoured, two-decker ram."