What is the term for the large discharge opening on a fire hydrant?

The term for the large discharge opening on a fire hydrant is known as the steamer port. This specific port is designed to accommodate the large hoses typically used by fire departments to deliver significant volumes of water quickly during firefighting operations. The steamer port allows for faster and more efficient water flow, which is critical in emergency situations where time is of the essence.

The other terms listed do not accurately describe the large opening on a hydrant. The discharge valve usually refers to the mechanism that controls water flow, while a supply port is generally utilized for connecting the water supply line from the hydrant to the fire apparatus. The control valve is another component that manages flow within the system but does not specifically designate the large discharge point. Thus, steamer port is the correct term for that particular function on a fire hydrant.