nozzle

n. spout that controls the flow of a liquid from a pipe, mouth of a hose; nose (Slang)

A nozzle is a mechanical device designed to control the characteristics of a fluid flow as it exits (or enters) an enclosed chamber or pipe.A nozzle is often a pipe or tube of varying cross sectional area, and it can be used to direct or modify the flow of a fluid (liquid or gas). Nozzles are frequently used to control the rate of flow, speed, direction, mass, shape, and/or the pressure of the stream that emerges from them.
See more at Wikipedia.org...

Noun
1. a projecting spout from which a fluid is discharged
(synonym) nose
(hypernym) spout
(hyponym) showerhead
(part-holonym) oilcan
2. informal terms for the nose
(synonym) beak, honker, hooter, snoot, snout, schnozzle, schnoz
(hypernym) nose, olfactory organ
(classification) United States, United States of America, America, US, U.S., USA, U.S.A.

(n.)
The nose; the snout; hence, the projecting vent of anything; as, the nozzle of a bellows.
  

(n.)
A short tube, usually tapering, forming the vent of a hose or pipe.
  

(n.)
A short outlet, or inlet, pipe projecting from the end or side of a hollow vessel, as a steam-engine cylinder or a steam boiler.
  

As used in power water reactors and boiling water reactors, the interface (inlet and outlet) between reactor plant components (pressure vessel, coolant pumps, steam generators, etc.) and their associated piping systems.