Chest, Strongbox, Treasury, Funds. (Merriam – Webster)
A strongbox or small chest for holding valuables. (Oxford Dictionaries)
The funds or financial reserves of an organisation. (Oxford Dictionaries)
A large, strong box in which money or valuable objects are kept. (Cambridge Dictionary)
A coffer is a large strong chest used for storing valuable objects such as money or gold and silver. (Collins Dictionary)
The coffers of an organisation consist of the money that it has to spend, imagined as being collected together in one place. (Collins Dictionary)
Late 17th Century Small Carved Oak Coffer.