a wooden tub, usually large enough to accommodate several persons, that is filled with hot aerated water and often equipped with a thermostat and whirlpool: used for recreation or physical therapy and often placed out of doors, as on a porch.
a bottle for aerated water, fitted with a bent tube through the neck, the water being forced out, when a valve is opened, by the pressure on its surface of the gas accumulating within the bottle.
