bain-marie (“BAHN mah-REE”) is a container placed in water-bath in the oven.

Used to keep food or utensils warm, or to slowly cook items. Custards are an example, in which a low temperature is desired, so as to avoid burning. Commercial steam tables are another example of the bain-marie.

Illustration from Isabella Beeton’s Mrs Beeton’s household management: a guide to cookery in all branches. London: Ward, Lock & Co, 1907.