1. The act or process of suddenly cutting something off or a sudden termination; removal: Jim's surgical abscission was neat and the wound was healing very well.

The unexpected abscission of the speeches at the rally were welcomed by the crowd.

2. In botany, the normal separation of flowers, fruit, and leaves from plants or the natural process by which leaves or other parts are shed from a plant: In the fall, people can see the abscissions of the leaves as they fall from the trees and are scattered on the ground.

The abscission zone is a layer of weak, thin-walled cells that form across the base of a plant part where the break eventually occurs.