Definition of gundeck (Entry 2 of 2) slang. : to fake or falsify especially by writing up (as a series of official reports) as if meeting requirements but actually without having carried out the required procedures.

Where did the term Gundecking come from?

The believe the term originated in the Royal navy in the 19th century when the deck below the upper deck on British sailing ships-of-war was called the gundeck although it carried no guns. This false deck was constructed to deceive enemies as to the amount of armament carried, thus the gundeck was a falsification.

What is gun deck Navy slang?

The term "gun deck" is also navy slang for fabricating or falsifying something.