\Kelp\, n. [Formerly kilpe; of unknown origin.]
1. The calcined ashes of seaweed, -- formerly much used in
   the manufacture of glass, now used in the manufacture of
   iodine.
2. (Bot.) Any large blackish seaweed.
Note: {Laminaria} is the common kelp of Great Britain;
      {Macrocystis pyrifera} and {Nereocystis Lutkeana} are
      the great kelps of the Pacific Ocean.
{Kelp crab} (Zo["o]l.), a California spider crab ({Epialtus
   productus}), found among seaweeds, which it resembles in
   color.
{Kelp salmon} (Zo["o]l.), a serranoid food fish ({Serranus
   clathratus}) of California. See {Cabrilla}.