sea·​floor ˈsē-ˌflȯr How to pronounce seafloor (audio)
variants or less commonly sea floor
plural seafloors also sea floors
: the floor of a sea or ocean : seabed
The Earth's crust, in this view, is divided into several immense plates that make up the continents and seafloors, and that all float on a hot, plastic, subterranean "mantle."Walter Sullivan

Examples of seafloor in a Sentence

Recent Examples on the Web To be classified as a seamount, the summits must tower at least 3,300 above the surrounding seafloor. Mark Price, Miami Herald, 15 Feb. 2024 The mountainous seafloor was two miles deep in places. Robert Klara, Smithsonian Magazine, 15 Feb. 2024 Among these sensors were several sonar devices, designed to detect underwater objects using the bounce of sound waves between the surface and seafloor. Sam Walters, Discover Magazine, 1 Feb. 2024 Example of seafloor multibeam bathymetry data showing the coral mound features located on the Blake Plateau. Li Cohen, CBS News, 23 Jan. 2024 Disturbing the seafloor could lead to plumes of sediment rising through the water column, which could disturb sea life for hundreds of kilometers, impacting Norway’s neighbors—such as Iceland, Greenland, and the Faroe Islands—as well as the Arctic more broadly. Eliza Gkritsi, WIRED, 12 Jan. 2024 Surrounded by muck and covered in grime, a large object sat on the seafloor off the southern coast of Italy. Aspen Pflughoeft, Miami Herald, 6 Feb. 2024 Xlinks plans to bury their cables under the European continental shelf, about 700 meters beneath the seafloor. IEEE Spectrum, 30 Nov. 2023 In once case in August, UM scientists also did the opposite — planting nursery and lab-grown corals on the seafloor two miles east of Key Biscayne. Alie Skowronski, Sun Sentinel, 11 Jan. 2024 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'seafloor.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

1853, in the meaning defined above

Time Traveler
The first known use of seafloor was in 1853

Dictionary Entries Near seafloor

Cite this Entry

“Seafloor.” Dictionary, Merriam-Webster, Accessed 25 Feb. 2024.

Kids Definition


sea·​floor -ˌflō(ə)r How to pronounce seafloor (audio)
: seabed

More from Merriam-Webster on seafloor

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