Kelp \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.

Source: Webster's Revised Unabridged Dictionary (1913)