A watertight chamber used in underwater construction, such as bridge foundations or tunnels. Technical term in civil engineering.
The caisson method was used for the construction of the bridge piers.
caisson disease; the bends
Compound of 潜 (せん, 'submerge, dive') and 函 (かん, 'box, container'), literally 'submerged box'. The term was coined in Japanese to describe a caisson used in underwater construction.