Gasket \Gas"ket\, n. [Cf. F. garcette, It. gaschetta, Sp. cajeta caburn, garceta reef point.]

1. (Naut.) A line or band used to lash a furled sail securely. Sea gaskets are common lines; harbor gaskets are plaited and decorated lines or bands. Called also casket.

2. (Mech.)
   (a) The plaited hemp used for packing a piston, as of the steam engine and its pumps.
   (b) Any ring or washer of packing.

Source: Webster's Revised Unabridged Dictionary (1913)