Abatis

Abatisses are used in war to keep the approaching enemy under fire for as long as possible.
Abatis in front of the Union trench lines at Petersburg in 1865

An abatis, abattis, or abbattis is a field fortification consisting of an obstacle formed (in the modern era) of the branches of trees laid in a row, with the sharpened tops directed outwards, towards the enemy. The trees are usually interlaced or tied with wire. Abatis are used alone or in combination with wire entanglements and other obstacles.[1]

In Slavic languages it is known as zaseka, a position behind sharpened objects.