n.1. a. The floor of a fireplace, usually extending into a room and paved with brick, flagstone, or cement.
b. A fireplace: a blazing fire in the hearth.
2. Family life; the home.
3. Metallurgy a. The lowest part of a blast furnace or cupola, from which the molten metal flows.
b. The bottom of a reverberatory furnace, where ore is exposed to the flame.
4. The fireplace or brazier of a blacksmith's forge.