bivouack

Noun

bivouac (plural bivouacs)

1. An encampment for the night, usually without tents or covering.
   • Townsend hare inhabit this area, particularly above the cabin, and a skier is likely to have one explode from a tree well and disappear into the whiteness as he skis by. Life is a constant bivouac for them -- they spend days huddled in tree wells during storms -- but I suspect they are as content...2014, Patrick Armstrong, The Log of a Snow Survey, →ISBN
2. Any temporary encampment.
3. A temporary shelter constructed generally for a few nights.
   • Behold the Mansion reared by Dædal Jack!
     See the Malt stored in many a plethoric sack,
     In the proud cirque of Juan's bivouac!1977, K.M. Elizabeth Murray, Caught in the Web of Words, Oxford: Oxford University Press, page 63
4. (dated) The watch of a whole army by night, when in danger of surprise or attack.
5. A structure formed by migratory ants out of their own bodies to protect the queen and larvae.
   • Army ants (genus Eciton) migrating and gathering in a bivouac.2026 July 8, “Observe an Eciton army ant colony migrating by night and forming a bivouac nest entirely out of themselves”, in Britannica

See all 8 meanings of bivouac