En flûte

[1] Some warships, ships of the line or frigates, were occasionally used with limited artillery, by reducing the number and calibre of their guns.

This tactic was most relevant in the Age of Sail, when gun decks took up most of the space on a warship above the waterline.

Reducing the artillery of a ship of the line or a frigate entailed a dramatic saving in space, since the removal of certain guns meant that their gunners (and their equipment and provisions) were not needed.

A typical ship of the line armed en flûte would have her armament cut down to a quarter of her maximum, and could accommodate over 1,000 troops.

[2] As an opposite, a ship fitted with her entire complement of sailors, guns and ammunition was said to be armed "en guerre" (French: "readied for war").