Found 2 items, similar to cofferdam.
English → English (WordNet) Definition: cofferdam cofferdam n : large watertight chamber used for construction under water [syn: caisson, pneumatic caisson]
English → English (gcide) Definition: Cofferdam Cofferdam \Cof"fer*dam\, n. A water-tight inclosure, as of piles packed with clay, from which the water is pumped to expose the bottom (of a river, etc.) and permit the laying of foundations, building of piers, etc. [1913 Webster]