cofferdam

noun

1. A temporary watertight enclosure used to create a dry foundation for building bridges and other structures over water.

   “He stood full six feet in height, with noble shoulders, and a chest like a coffer-dam.”

   “Downstream there was a small wooden cofferdam and when he woke there were naked children splashing in the pool there and he rose and wrapped his jacket about his waist and walked out along the bank where he could sit and watch them.”

   “At fixed injection volume of PVC gels solution, the curvature of MLAs [(microlens arrays)] obtained with patterned electrode substrates at fixed sizes of cofferdam can be tuned by changing the preparation voltage.”

   “Where the viaduct crosses the lake, the piles will be bored directly into the lakebed, using a cofferdam to hold back the water while the pier is built.”

2. An empty space that acts as a protective barrier between two floors or bulkheads on a ship.
3. (obsolete)Synonym of dental dam (“barrier to keep the teeth dry during dental work”) (dental sense).

   “I refer to Dr. Barnum, who has given us the coffer-dam. I cannot detain you while I describe the immense benefit which his application of a very simple material has conferred on the public.”

   “Dr. La Roche then first we are informed made the claim that he knew of and used rubber for a coffer dam prior to Barnum.”