Kelp /(kĕlp)/

Kelp

n.
  1. The calcined ashes of seaweed, -- formerly much used in the manufacture of glass, now used in the manufacture of iodine.
  2. Any large blackish seaweed. (Bot.)

Phrases & Compounds
Kelp crab
a California spider crab (Epialtus productus), found among seaweeds, which it resembles in color.
Kelp salmon
a serranoid food fish (Serranus clathratus) of California. See Cabrilla.