Dictionary.com
Thesaurus.com
Synonyms

caisson

American  
[key-suhn, -son] / ˈkeɪ sən, -sɒn /

noun

  1. a structure used in underwater work, consisting of an airtight chamber, open at the bottom and containing air under sufficient pressure to exclude the water.

  2. a boatlike structure used as a gate for a dock or the like.

  3. Nautical.

    1. Also called camel, pontoon.  a float for raising a sunken vessel, sunk beside the vessel, made fast to it, and then pumped out to make it buoyant.

    2. a watertight structure built against a damaged area of a hull to render the hull watertight; cofferdam.

  4. a two-wheeled wagon, used for carrying artillery ammunition.

  5. an ammunition chest.

  6. a wooden chest containing bombs or explosives, used formerly as a mine.

  7. Architecture. coffer.


caisson British  
/ ˈkeɪsən, kəˈsuːn /

noun

  1. a watertight chamber open at the bottom and containing air under pressure, used to carry out construction work under water

  2. a similar unpressurized chamber

  3. a watertight float filled with air, used to raise sunken ships See also camel

  4. a watertight structure placed across the entrance of a basin, dry dock, etc, to exclude water from it

    1. a box containing explosives, formerly used as a mine

    2. an ammunition chest

    3. a two-wheeled vehicle containing an ammunition chest

  5. another name for coffer

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Word Forms

  • caissoned adjective

Etymology

Origin of caisson

1695–1705; < French, Middle French < Old Provençal, equivalent to caissa box ( case 2 ) + -on augmentative suffix

Vocabulary lists containing caisson

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

For years, members of the tiny preservation society — their ages now ranging from 60s to 80s — have flown out in helicopters, landing on the caisson.

From Los Angeles Times • Oct. 26, 2025

And in ceremonies for Army and Marine Corps officers who were colonels or above, there is a riderless horse that walks behind the caisson.

From Seattle Times • Apr. 12, 2024

A soldier, gingerly, with almost mechanical precision, removed the silver urn containing Megellas’s cremated remains from the caisson and carried it to the gravesite.

From Washington Post • Sep. 6, 2022

On November 11, 1921, the Unknown was placed on a horse-drawn caisson and carried in a procession through Washington, D.C. and across the Potomac River.

From Fox News • Oct. 4, 2021

Crossing slowly in the rain a few feet above the flood, pressed tight in the crowd, the box of an artillery caisson just head, I looked over the side and watched the river.

From "A Farewell To Arms" by Ernest Hemingway