Bungee

bun·gee cord n. Americans spell it bungie.
Also called Shock Cord.

An elasticized rubber cord covered with nylon or polyester braid, used to fasten, bear weight, or absorb shock.

Used on sea kayak decks to provide paddle parks, chart parks and so on. Spray skirts often have bungee around the hem to keep them tight to the coaming.

Putting a bungee inside tubular webbing creates a retractable pigtail.

[Alteration of bunjie, rubber.]