Bivouac (noun)
biv-wak
A temporary camp without tents or cover, used especially by soldiers or mountaineers.
Early 18th century (denoting a night watch by the whole army): from French, probably from Swiss German Bîwacht ‘additional guard at night’, apparently denoting a citizens’ patrol supporting the ordinary town watch.
Example sentences
“As the men set up the bivouac, we built a fire, the desert got cold in the night.”