Kelp

[kelp] /kɛlp/

noun
1.
any large, brown, cold-water seaweed of the family Laminariaceae, used as food and in various manufacturing processes.
2.
a bed or mass of such seaweeds.
3.
the ash of these seaweeds.
verb (used without object)
4.
to burn these seaweeds for their ash.
/kɛlp/
noun
1.
any large brown seaweed, esp any in the order Laminariales
2.
the ash of such seaweed, used as a source of iodine and potash
n.

1660s, from Middle English culpe (late 14c.), of unknown origin. Kelper “native or inhabitant of the Falkland Islands” is attested from 1960.
kelp
(kělp)
Any of various brown, often very large seaweeds that grow in colder ocean regions. Kelps are varieties of brown algae of the order Laminariales, with some species growing over 61 m (200 ft) long. Kelps are harvested as food (primarily in eastern Asia), as fertilizer, and for their sodium and potassium salts, used in industrial processes. Kelps are also a source of thickening agents and colloid stabilizers used in many commercial products. See more at brown alga.