Bemused not only by Claire’s peculiar dress—or lack of it—by the sheer impossibility of her presence—English ladies simply aren’t found in the Highlands in 1743—the Scotsmen decide to take her with them when they decamp under cover of darkness.
-- Diana Gabaldon, The Outlandish Companion, 1999
Louis XII of France at the time was invading Italy much the way his dwarf Uncle Charles had, and we were close enough we could decamp immediately back to Rome in a day or two.
-- John Faunce, Lucrezia Borgia, 2010
From the French descamper, decamp emerged in English in the late 1600s. It is a combination of Latin roots dis + campus, literally meaning "away from open field."