Gasket

noun

1. A length of rope used for reefing a sail, or holding a stowed sail in place.
2. Any mechanical seal that serves to fill the space between two objects, generally to prevent leakage between the two objects while under compression.
3. A material which may be clamped between faces and acts as a static seal. Gaskets may be cut, formed, or molded to the desired configuration.
4. Any of a wide variety of seals or packings used between matched machine parts or around pipe joints to prevent the escape of a gas or fluid.