definition of
caisson

[1] #1 caisson n. [coffer, lacuna] an ornamental sunken panel in a ceiling or dome. wn

[2] #2 caisson n. a two-wheeled military vehicle carrying artillery ammunition. wn

[3] #3 caisson n. [ammunition chest] a chest to hold ammunition. wn

[4] #4 caisson n. [pneumatic caisson, cofferdam] large watertight chamber used for construction under water. wn