Definition
In a jet engine, a shaped opening at the rear of the engine through which hot exhaust gases are expelled. The nozzle's narrowing shape accelerates the exhaust stream as it leaves the engine, converting heat and pressure energy into high-velocity gas flow that produces thrust.
Plain English
The hole at the back of a jet engine where the hot gases shoot out. It is shaped to speed the gases up as they leave, and that fast-moving stream is what pushes the airplane forward.
Context Anchor
Seen in jet engine basics when describing how exhaust flow is turned into forward push.
Derivation
From 'nose' plus the diminutive ending '-le', so literally 'a little nose' — the small spout or projecting outlet on a container or pipe. The aviation use keeps that core idea: a shaped outlet that directs and controls a flow leaving the engine.
Why Pilots Care
Nozzle shape and area directly affect thrust, engine efficiency, and fuel consumption during all phases of jet flight.
Analogy
Think of pinching the end of a garden hose. The water leaving the hose speeds up because the opening narrows. A jet engine nozzle does the same thing to hot exhaust gas.
Intuition Check
Do not think of a nozzle only as something that sprays liquid. In a jet engine, the nozzle controls the direction and speed of hot gas leaving the engine.
Example Sentence 1
Hot gases leaving the turbine are accelerated through the nozzle to produce thrust.
Example Sentence 2
During climb the pilot monitors how nozzle geometry influences exhaust velocity and overall engine performance.