Sheathing

Part of speech: noun (n.)

1. That which sheathes. Specifically:

2. The casing or covering of a ship's bottom and sides; the materials for such covering; as, copper sheathing.

Part of speech: participle (p.)

from Sheathe. Inclosing with a sheath; as, the sheathing leaves of grasses; the sheathing stipules of many polygonaceous plants.