Definition of abattis:

part of speech: noun

Piles of trees or their larger branches, with sharpened points outward, laid down for the protection of troops.

Usage examples:

• Hardly had I written the above when I was hunted from my lair, and rushed down 200 steep feet, and then up some 500 or 600 on the other side of the stream, through an abattis of clinging undergrowth that made a severe toil of what could never have been a pleasure. T. R. Swinburne in "A Holiday in the Happy Valley with Pen and Pencil".

• In advance of these was a double row of abattis L. Carroll Judson in "Sages and Heroes of the American Revolution".

• In most of the woods they had felled trees, and thrown them across the road; but as these abattis were without defenders, we experienced no other inconvenience than what arose from loss of time; being obliged to halt on all such occasions till the pioneers had removed the obstacle. G. R. Gleig in "The Campaigns of the British Army at Washington and New Orleans 1814-1815".

• Orchards had been cut down to serve as abattis and barrels of earth were ready to roll down upon the British. Allen French in "The Siege of Boston".