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

When the beach is at low tide, visitors can explore the large sea cave and tide pools, or hop on a kayak to paddle through coastal kelp beds. —Nicole Kliest, Vogue, 20 Oct. 2025

Reef Check Foundation and Ecologia, Cielo, Mar y Tierra received $100,000 to assess the health of kelp forests in San Diego and Tijuana as vital natural defenses against climate change and ocean conditions around the water treatment outflows. —Linda McIntosh, San Diego Union-Tribune, 20 Oct. 2025

Each loop of the driveway produced an impassable snowdrift in winter, but by then Carol and Mike were on the coast, watching waving kelp fronds from their living room. —Literary Hub, 17 Oct. 2025

Among the casualties are the region’s rich kelp forests, which contribute upwards of $52 billion to the global economy and sequester nearly a megaton of carbon from the atmosphere every year. —JSTOR Daily, 17 Oct. 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