a casket, chest, or trunk; especially, one used for keeping money or other valuables.-fig.: treasure or funds; -- usually in the plural.-a panel deeply recessed in the ceiling of a vault, dome, or portico; a caisson.-a trench dug in the bottom of a dry moat, and extending across it, to enable the besieged to defend it by a raking fire.-the chamber of a canal lock; also, a caisson or a cofferdam.-to put into a coffer.-to secure from leaking, as a shaft, by ramming clay behind the masonry or timbering.-to form with or in a coffer or coffers; to furnish with a coffer or coffers.