#1 caisson n. [coffer, lacuna] an ornamental sunken panel in a ceiling or dome. wn
#2 caisson n. a two-wheeled military vehicle carrying artillery ammunition. wn
#3 caisson n. [ammunition chest] a chest to hold ammunition. wn
#4 caisson n. [pneumatic caisson, cofferdam] large watertight chamber used for construction under water. wn
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