A fascine (pronounced /fəˈsiːn/) is a rough bundle of brushwood or other material used for strengthening an earthen structure, or making a path across uneven or wet terrain. Typical uses are protecting the banks of streams from erosion (a fascine mattress), covering marshland, or providing ground improvement in a manner similar to that of modern geotextiles.
In war they have often been used to help armies – in modern times, especially tanks and other vehicles – cross trenches, valleys, marshes, muddy or uneven terrain, etc.