Envelopment (noun)

1. The act of enveloping or the state of being enveloped.
2. A military maneuver in which an attacking force surrounds and isolates an enemy.
3. The act or process of surrounding or covering completely.

Origin:

Mid 19th century: from envelop + -ment.

Examples:

1. The envelopment of the town by the forest was complete.
2. The envelopment of the enemy was accomplished within hours.
3. The envelopment of the city by the invading army was a significant event in the war.
4. The envelopment of the planet by the atmosphere provides a protective shield.
5. The envelopment of the building by the scaffolding was necessary for the repair work.