Bivouac meaning : An encampment for the night, usually without tents or covering. Any temporary encampment. A temporary shelter constructed generally for a few nights. The watch of a whole army by night, when in danger of surprise or attack. A structure formed by migratory ants out of their own bodies to protect the queen and larvae. To set up camp. To watch at night or be on guard, as a whole army. To encamp for the night without tents or covering.