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 original collagen version is found online alongside PDRN, Cera-nol, and sea kelp iterations. — Sophie Dunne, Footwear News, 14 Sep. 2026

Also, in terms of looking for the best spots to snorkel, look for kelp forests and rock reefs. — Jaclyn Cosgrove, Los Angeles Times, 10 Sep. 2026

The Joico HydraSplash Hydrating Shampoo swaps the usual suspects for keratin (a protective protein) and natural hydrators like coconut water and sea kelp to replenish dry hair while thoroughly cleansing it. — Madison San Miguel, Allure, 5 Sep. 2026

Snorkelers and divers can swim past underwater kelp forests, awe-inspiring volcanic formations, and rocky reefs. — Cu Fleshman, Travel + Leisure, 27 Aug. 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