A passageway through jet bits that causes the drilling fluid to be ejected from the bit at high velocity.
The jet of mud clears the bottom of the hole.
Nozzles come in different sizes that can be interchanged on the bit to adjust the velocity with which the mud exits the bit.
The part of the fuel system of an engine that has small holes in it to permit fuel to enter the cylinder.
Properly known as a fuel-injection nozzle, but also called a spray valve.
The needle valve is directly above the nozzle.