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

Additionally, fish meal and kelp are excellent organic fertilizers for fruit trees. —Sj McShane, Martha Stewart, 10 May 2026

Desserts, meanwhile, will be dreamed up by Matt Tinder, the former pastry chef at Coi; dishes there include offerings like raw chocolate, roasted kelp, and date. —Nicole Hoey, Robb Report, 7 May 2026

Lindell’s lab, funded by MARINER, focused on improving crop yield by selectively breeding kelp with desirable qualities — such as nonreproductive capabilities to prevent interbreeding with wild kelp — so that, down the line, farmers could scale up their kelp production. —ABC News, 6 May 2026

And although the sea lions and other species have since recovered, kelp forests in many places, including off the Sonoma and Mendocino coasts, are still struggling. —Paul Rogers, Mercury News, 3 May 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