kelp

noun

ˈkelp 

plural kelps or kelp

1

a

: any of various large marine brown algae that are large seaweeds (order Laminariales) growing in cool waters

Only canopy-forming kelp are visible on the sea surface.

—Glenn Scherer

Kelps grow fast, drawing on all the minerals and vitamins and nutrients they can from the watershed and the sun.

—Zachariah Bryan

… thickets of kelp forming submarine forests in the bay.

—Jeff Phillips

see also bladder kelp, bull kelp, giant kelp

b

: a mass or growth of large seaweeds

The kelp near the outer islands teems with marine plants and animals in far greater abundance than it does closer to the coast …

—John L. Stein

2

a

: a blade (see blade entry 1 sense 2e) of kelp that is usually dried and used as food (as in sushi or soups)

b

: a dietary supplement containing processed kelp

c

: the ashes of seaweed used formerly especially as a source of iodine

Examples of kelp in a Sentence

Recent Examples on the Web

Along some parts of the California coast, from Marin to Mendocino, scientists have been replanting kelp and working to remove overgrown urchin populations to help restore kelp forests that were depleted when sea star populations crashed. —Paul Rogers, Mercury News, 5 Aug. 2025

The whale was seen rubbing a kelp patty on its upper jaw and although the group was lucky enough to see the behavior, kelping can lead to humpbacks becoming entangled, boaters said. —Paloma Chavez august 5, Sacbee.com, 5 Aug. 2025

Seaweed, particularly sugar kelp, naturally fills these gaps with a potent mix of insoluble fibers such as fucoidan, beta-glucan, alginate, and cellulose. —Dianne Plummer, Forbes.com, 18 July 2025

These may resemble stringy algae or kelp plants that attach to rocks and other objects within the spring. —Monica Cull, Discover Magazine, 4 July 2025

Word History

Etymology

Middle English culp

First Known Use

14th century, in the meaning defined at sense 1a

Phrases Containing kelp

• bladder kelp
• bull kelp
• giant bladder kelp
• giant kelp
• kelp bass

Rhymes for kelp

• help
• skelp
• whelp
• yelp

Kids Definition

kelp

noun

ˈkelp 

: any of various large brown seaweeds

also : a mass of these

Medical Definition

kelp

noun

ˈkelp 

1

: any of various large marine brown algae that are large seaweeds (order Laminariales) growing in cool waters

2

a

: a dietary supplement containing processed kelp

b

: the ashes of seaweed used formerly especially as a source of iodine