The word 'envelopment' is correct and usable in written English
It is a noun that means the act of surrounding or enclosing something completely. One could use it in a sentence like: The dense fog created an envelopment around the city, making it difficult to see more than a few feet in front of you.
Alfred von Schlieffen's vision of a grand envelopment was impossible because the technologies of mobility and communication lagged far behind the destructive power of 20th-century weapons.
A frontal attack would immobilize the enemy while forces on the flanks would execute a double envelopment, forming a pocket called a Kessel ("cauldron") around the enemy.
Threatened with envelopment, the Japanese fell back from Wan-t'ing, which Sultan's troops promptly occupied.
The same applied to the one fought by Hannibal at Cannae in 216 bc; this owed its exceptionally decisive character to the envelopment of the Roman infantry by two cavalry arms instead of one.
Once convinced of the developing German threat on the French left flank, Joffre shifted his forces and created a new French army, the 6th, under his direct authority, to counter the threat of German envelopment.
Meanwhile, the assault by the German 6th and 7th armies on the defenses of the French eastern frontier had already proved a predictably expensive failure, and the German attempt at a partial envelopment pivoted on Verdun was abandoned.
The Serbian Army, meanwhile, to avoid double envelopment, had begun an arduous winter retreat westward over the Albanian mountains to refuge on the island of Corfu.
Morgan's successful double envelopment routed the British, and the militia soldiers' actions at Cowpens are generally credited with having ensured a rare American victory.
The premature inward wheel of Kluck's 1st Army before Paris had been reached thus exposed the German extreme right wing to a flank attack and a possible counter-envelopment.
Approximately one-third of Poland's forces were concentrated in or near the Polish Corridor (in northeastern Poland), where they were perilously exposed to a double envelopment from East Prussia and the west combined.
From a hotly contested field (don't miss the Alpine Salt Mud Bath and Balinese Facial), I would single out, among my own treatments, the Calcot Rose Blossom Envelopment Wrap.
