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

Key ingredients: Alma, sea kelp, rose hip How To apply: Use this in place of hair spray. —Conçetta Ciarlo, Vogue, 1 May 2025

As countries scrambled by tapping into fertilizer reserves and using alternatives such as sea kelp, the embargo put a serious strain on global food supplies. — Made By History, Time, 15 Apr. 2025

Urchins devour kelp, which sequesters carbon and serves as shelter and food for a vast array of marine life. —Lila Seidman, Los Angeles Times, 11 Apr. 2025

Glamour testers liked that the formula has sea salt to lend texture, delivering those covetable beachy waves, but also boasts sea kelp, a moisturizing ingredient that helps prevent any crunch. —Brigitt Earley, Glamour, 2 Apr. 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