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

The Sea to Soul treatment, for example, uses soothing Pacific seaweed fronds, warm kelp water, and a green tea seaweed salt glow exfoliation to target muscle tension and a glacial clay mask to firm the skin. — Condé Nast, Condé Nast Traveler, 6 Oct. 2026

The leading hypothesis is that the whale calves are suffering infections from marine bacteria that can enter their bodies through injuries inflicted by kelp gulls, Uhart said. — ABC News, 2 Oct. 2026

When kelp doesn’t do well, the animals that depend on it — such as rockfish — similarly suffer. — Lila Seidman, Los Angeles Times, 1 Oct. 2026

They’re protected from sharks by all the kelp growth in that spot, explained a volunteer docent who also shared that the beach’s live cam gets rather steamy in January. — David G. Allan, CNN Money, 22 Sep. 2026

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